Securities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Securities
Available-for-sale, amortized cost	$ 383,631	$ 414,457
Available-for-sale, gross unrealized gains	4,282	1,904
Available-for-sale, gross unrealized losses	(3,554)	(14,671)
Total available-for-sale securities	384,359us-gaap_AvailableForSaleSecurities	401,690us-gaap_AvailableForSaleSecurities
Total held-to-maturity securities	2,133,804us-gaap_HeldToMaturitySecurities	1,849,526us-gaap_HeldToMaturitySecurities
Held-to-maturity, gross unrealized gains	17,605	13,023
Held-to-maturity, gross unrealized losses	(20,038)	(51,427)
Held-to-maturity securities, fair value	2,131,371	1,811,122
GSE issuance REMICs and CMOs
Securities
Available-for-sale, amortized cost	266,946	292,131
Available-for-sale, gross unrealized gains	3,608	1,077
Available-for-sale, gross unrealized losses	(1,556)	(7,134)
Total available-for-sale securities	268,998	286,074
Total held-to-maturity securities	1,575,402	1,474,506
Held-to-maturity, gross unrealized gains	14,536	12,877
Held-to-maturity, gross unrealized losses	(14,041)	(33,925)
Held-to-maturity securities, fair value	1,575,897	1,453,458
Non-GSE issuance REMICs and CMOs
Securities
Available-for-sale, amortized cost	5,071	7,516
Available-for-sale, gross unrealized gains	34	57
Available-for-sale, gross unrealized losses	(1)	(1)
Total available-for-sale securities	5,104	7,572
Total held-to-maturity securities	2,482	3,833
Held-to-maturity, gross unrealized gains	31	61
Held-to-maturity, gross unrealized losses	(7)	(10)
Held-to-maturity securities, fair value	2,506	3,884
GSE pass-through certificates
Securities
Available-for-sale, amortized cost	12,919	16,120
Available-for-sale, gross unrealized gains	640	770
Available-for-sale, gross unrealized losses	(2)	(2)
Total available-for-sale securities	13,557	16,888
Total held-to-maturity securities	281,685	282,473
Held-to-maturity, gross unrealized gains	2,442	85
Held-to-maturity, gross unrealized losses	(3,877)	(10,089)
Held-to-maturity securities, fair value	280,250	272,469
Total residential mortgage-backed securities
Securities
Available-for-sale, amortized cost	284,936	315,767
Available-for-sale, gross unrealized gains	4,282	1,904
Available-for-sale, gross unrealized losses	(1,559)	(7,137)
Total available-for-sale securities	287,659	310,534
Total held-to-maturity securities	1,859,569	1,760,812
Held-to-maturity, gross unrealized gains	17,009	13,023
Held-to-maturity, gross unrealized losses	(17,925)	(44,024)
Held-to-maturity securities, fair value	1,858,653	1,729,811
Multi-family mortgage-backed securities
Securities
Total held-to-maturity securities	154,381
Held-to-maturity, gross unrealized gains	554
Held-to-maturity, gross unrealized losses	(590)
Held-to-maturity securities, fair value	154,345
Obligations of GSEs
Securities
Available-for-sale, amortized cost	98,680	98,675
Available-for-sale, gross unrealized losses	(1,982)	(7,522)
Total available-for-sale securities	96,698	91,153
Total held-to-maturity securities	119,336	88,128
Held-to-maturity, gross unrealized gains	42
Held-to-maturity, gross unrealized losses	(1,523)	(7,403)
Held-to-maturity securities, fair value	117,855	80,725
Fannie Mae stock
Securities
Available-for-sale, amortized cost	15	15
Available-for-sale, gross unrealized losses	(13)	(12)
Total available-for-sale securities	2	3
Other
Securities
Total held-to-maturity securities	518	586
Held-to-maturity securities, fair value	$ 518	$ 586

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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