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

Schedule of Available-for-sale Securities Reconciliation (Details)

Schedule of Available-for-sale Securities Reconciliation (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	$ 35,068,573	$ 29,396,680
Unamortized Premium	1,362,059	1,370,959
Accretable Purchase Discount	723,571	700,671
Credit Reserve Purchase Discount	1,194,749	653,613
Amortized Cost	26,087,090	20,856,658
Unrealized Gain	579,177	544,198
Unrealized Loss	727,351	180,037
Available-for-sale securities, at fair value	25,938,916	21,220,819
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	24,795,205	20,023,621
Unamortized Premium	1,284,982	1,302,535
Accretable Purchase Discount	38,957	24,638
Credit Reserve Purchase Discount	0	0
Amortized Cost	22,812,501	18,359,746
Unrealized Gain	22,097	53,104
Unrealized Loss	715,652	174,125
Available-for-sale securities, at fair value	22,118,946	18,238,725
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	10,273,368	9,373,059
Unamortized Premium	77,077	68,424
Accretable Purchase Discount	684,614	676,033
Credit Reserve Purchase Discount	1,194,749	653,613
Amortized Cost	3,274,589	2,496,912
Unrealized Gain	557,080	491,094
Unrealized Loss	11,699	5,912
Available-for-sale securities, at fair value	3,819,970	2,982,094
Interest-Only-Strip [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	3,228,729	2,941,772
Unamortized Premium	218,997	223,289
Accretable Purchase Discount	0	0
Credit Reserve Purchase Discount	0	0
Amortized Cost	218,997	223,289
Unrealized Gain	14,812	10,955
Unrealized Loss	50,244	39,156
Available-for-sale securities, at fair value	183,565	195,088
Interest-Only-Strip [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	5,196,493	5,614,925
Unamortized Premium	70,511	65,667
Accretable Purchase Discount	0	0
Credit Reserve Purchase Discount	0	0
Amortized Cost	70,511	65,667
Unrealized Gain	4,264	2,163
Unrealized Loss	2,606	2,746
Available-for-sale securities, at fair value	72,169	65,084
Fixed Income Securities [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	21,566,476	17,081,849
Unamortized Premium	1,065,985	1,079,246
Accretable Purchase Discount	38,957	24,638
Credit Reserve Purchase Discount	0	0
Amortized Cost	22,593,504	18,136,457
Unrealized Gain	7,285	42,149
Unrealized Loss	665,408	134,969
Available-for-sale securities, at fair value	21,935,381	18,043,637
Fixed Income Securities [Member] \| Mortgage-backed Securities, Issued by Private Enterprises [Member]
Debt Securities, Available-for-sale [Line Items]
Principal/Current Face	5,076,875	3,758,134
Unamortized Premium	6,566	2,757
Accretable Purchase Discount	684,614	676,033
Credit Reserve Purchase Discount	1,194,749	653,613
Amortized Cost	3,204,078	2,431,245
Unrealized Gain	552,816	488,931
Unrealized Loss	9,093	3,166
Available-for-sale securities, at fair value	$ 3,747,801	$ 2,917,010