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Securities Available-for-Sale (Comparative Summary of Mortgage-Backed Securities and Other Securities Available-for-Sale) (Details) - USD ($) $ in Thousands | Jun. 30, 2015 | Dec. 31, 2014
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | $ 642,226 | $ 771,935
Gross unrealized gains | 7,816 | 9,663
Gross unrealized losses | 9,830 | 10,359
Estimated fair value | 640,212 | 771,239
Pass-through Certificates | GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 259,523 | 292,162
Gross unrealized gains | 6,710 | 8,309
Gross unrealized losses | 1,417 | 1,131
Estimated fair value | 264,816 | 299,340
Real estate mortgage investment conduits (REMICs) | GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 348,813 | 408,328
Gross unrealized gains | 1,081 | 1,314
Gross unrealized losses | 8,378 | 9,192
Estimated fair value | 341,516 | 400,450
Real estate mortgage investment conduits (REMICs) | Non-GSE |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 844 | 1,060
Gross unrealized gains | 0 | 0
Gross unrealized losses | 33 | 34
Estimated fair value | 811 | 1,026
Real estate mortgage investment conduits (REMICs) | Mortgage Backed Securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 609,180 | 701,550
Gross unrealized gains | 7,791 | 9,623
Gross unrealized losses | 9,828 | 10,357
Estimated fair value | 607,143 | 700,816
Other securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 33,046 | 70,385
Gross unrealized gains | 25 | 40
Gross unrealized losses | 2 | 2
Estimated fair value | 33,069 | 70,423
Other securities | Equity investments-mutual funds |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 329 | 410
Gross unrealized gains | 0 | 0
Gross unrealized losses | 0 | 0
Estimated fair value | 329 | 410
Other securities | Corporate bonds |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Amortized Cost | 32,717 | 69,975
Gross unrealized gains | 25 | 40
Gross unrealized losses | 2 | 2
Estimated fair value | $ 32,740 | $ 70,013

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- Definition This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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