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

Derivative Instruments and Hedging Activities Put and Call Options for TBAs (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative, Notional Amount	$ 15,935,535	$ 18,802,500	$ 26,390,596	$ 21,998,381
Options Held [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,770,000	1,136,000	$ 2,000,000	$ 0
Derivative Financial Instruments, Liabilities [Member]
Derivative [Line Items]
Derivative, Notional Amount	4,105,269	3,543,593
Derivative, Fair Value, Net	(20,363)	(12,501)
Derivative Financial Instruments, Liabilities [Member] \| Options Held [Member]
Derivative [Line Items]
Derivative, Notional Amount	1,770,000	0
Derivative, Fair Value, Net	(7,003)	0
Derivative Financial Instruments, Assets [Member]
Derivative [Line Items]
Derivative, Notional Amount	21,576,266	21,708,907
Derivative, Fair Value, Net	253,564	324,182
Derivative Financial Instruments, Assets [Member] \| Options Held [Member]
Derivative [Line Items]
Derivative, Notional Amount	0	1,136,000
Derivative, Fair Value, Net	0	42,633
Long [Member] \| Options Held [Member]
Derivative [Line Items]
Derivative, Notional Amount	4,300,000	2,500,000
Short [Member] \| Options Held [Member]
Derivative [Line Items]
Derivative, Notional Amount	$ 2,530,000	$ 3,636,000