TWO Quarterly report pursuant to Section 13 or 15(d)

Derivative Instruments and Hedging Activities Schedule of Interest Rate Swaptions (Details)

Derivative Instruments and Hedging Activities Schedule of Interest Rate Swaptions (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional	$ 54,226,205,000	$ 36,528,169,000	$ 55,549,424,000	$ 41,330,283,000	$ 28,618,861,000	$ 31,226,878,000
Interest Rate Swaption [Member] \| Long [Member] \| Variable Income Interest Rate [Member]
Derivative [Line Items]
Cost Basis	(5,395,000)	(13,255,000)
Fair Value	$ (1,401,000)	$ (8,422,000)
Weighted Average Remaining Maturity	4 years 3 days	7 months 28 days
Interest Rate Swaption [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Cost Basis	$ (5,395,000)	$ (4,855,000)
Fair Value	$ (1,401,000)	$ (2,430,000)
Weighted Average Remaining Maturity	4 years 3 days	5 months 4 days
Interest Rate Swaption [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member]
Derivative [Line Items]
Cost Basis		$ (8,400,000)
Fair Value		$ (5,992,000)
Weighted Average Remaining Maturity		8 months 18 days
Interest Rate Swaption [Member] \| Long [Member] \| Fixed Income Interest Rate [Member]
Derivative [Line Items]
Cost Basis	$ (4,100,000)
Fair Value	$ (7,882,000)
Weighted Average Remaining Maturity	4 years 1 month 6 days
Interest Rate Swaption [Member] \| Long [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Cost Basis	$ (4,100,000)
Fair Value	$ (7,882,000)
Weighted Average Remaining Maturity	4 years 1 month 6 days
Interest Rate Swaption [Member] \| Short [Member] \| Fixed Income Interest Rate [Member]
Derivative [Line Items]
Cost Basis		$ (13,255,000)
Fair Value		$ (21,878,000)
Weighted Average Remaining Maturity		7 months 16 days
Interest Rate Swaption [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Cost Basis		$ (4,855,000)
Fair Value		$ (9,001,000)
Weighted Average Remaining Maturity		4 months 24 days
Interest Rate Swaption [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member]
Derivative [Line Items]
Cost Basis		$ (8,400,000)
Fair Value		$ (12,877,000)
Weighted Average Remaining Maturity		8 months 18 days
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member]
Derivative [Line Items]
Notional	$ 1,250,000,000	$ 1,700,000,000
Weighted Average Remaining Maturity	5 years 2 months 12 days	10 years
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate	2.05%	3.15%
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Notional	$ 1,250,000,000	$ 900,000,000
Weighted Average Remaining Maturity	5 years 2 months 12 days	10 years
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate	2.05%	3.16%
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member]
Derivative [Line Items]
Notional		$ 800,000,000
Weighted Average Remaining Maturity		10 years
Underlying Swap [Member] \| Long [Member] \| Variable Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate		3.14%
Underlying Swap [Member] \| Long [Member] \| Fixed Income Interest Rate [Member]
Derivative [Line Items]
Notional	$ 500,000,000
Weighted Average Remaining Maturity	10 years
Underlying Swap [Member] \| Long [Member] \| Fixed Income Interest Rate [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate	1.55%
Underlying Swap [Member] \| Long [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Notional	$ 500,000,000
Weighted Average Remaining Maturity	10 years
Underlying Swap [Member] \| Long [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate	1.55%
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member]
Derivative [Line Items]
Notional		$ 1,637,000,000
Weighted Average Remaining Maturity		10 years
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate		2.65%
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member]
Derivative [Line Items]
Notional		$ 845,000,000
Weighted Average Remaining Maturity		10 years
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Less Than Six Months Remaining Maturity [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate		2.66%
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member]
Derivative [Line Items]
Notional		$ 792,000,000
Weighted Average Remaining Maturity		10 years
Underlying Swap [Member] \| Short [Member] \| Fixed Income Interest Rate [Member] \| Six Months or Longer Remaining Maturity [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Derivative [Line Items]
Weighted Average Fixed Interest Rate		2.64%