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v3.19.1

Summary of Portfolio of Securities Available for Sale (Detail) - USD ($) $ in Thousands | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | $ 5,731,328 |  | $ 5,660,418 |
Gross Unrealized Gain |  | 55,387 |  | 46,339 |
Gross Unrealized Loss |  | 29,943 |  | 62,686 |
Fair Value |  | 5,756,772 |  | 5,644,071 |
Mortgage-Related Securities |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 2,828,433 |  | 2,953,957 |
Gross Unrealized Gain |  | 33,017 |  | 26,526 |
Gross Unrealized Loss |  | 10,690 |  | 20,201 |
Fair Value |  | 2,850,760 |  | 2,960,282 |
Mortgage-Related Securities | GSE certificates |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 1,380,756 |  | 1,705,336 |
Gross Unrealized Gain |  | 21,538 |  | 18,146 |
Gross Unrealized Loss |  | 6,663 |  | 15,961 |
Fair Value |  | 1,395,631 |  | 1,707,521 |
Mortgage-Related Securities | GSE CMOs |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 1,447,677 |  | 1,248,621 |
Gross Unrealized Gain |  | 11,479 |  | 8,380 |
Gross Unrealized Loss |  | 4,027 |  | 4,240 |
Fair Value |  | 1,455,129 |  | 1,252,761 |
Equity Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 32,162 |  | 32,162 |
Gross Unrealized Gain |  | 481 |  | 366 |
Gross Unrealized Loss |  | 515 |  | 1,977 |
Fair Value |  | 32,128 |  | 30,551 |
Equity Securities [Member] | Preferred stock |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 15,292 |  | 15,292 |
Gross Unrealized Gain |  | 0 |  |  |
Gross Unrealized Loss |  | 145 |  | 1,446 |
Fair Value |  | 15,147 |  | 13,846 |
Equity Securities [Member] | Mutual Funds and Common Stock |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost | [1] | 16,870 |  | 16,870 |
Gross Unrealized Gain | [1] | 481 |  | 366 |
Gross Unrealized Loss | [1] | 370 |  | 531 |
Fair Value | [1] | 16,981 |  | 16,705 |
Debt Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 2,870,733 |  | 2,674,299 |
Gross Unrealized Gain |  | 21,889 |  | 19,447 |
Gross Unrealized Loss |  | 18,738 |  | 40,508 |
Fair Value |  | 2,873,884 |  | 2,653,238 |
Debt Securities [Member] | U.S. Treasury obligations |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 29,659 |  |  |
Gross Unrealized Gain |  | 3 |  |  |
Gross Unrealized Loss |  | 0 |  |  |
Fair Value |  | 29,662 |  |  |
Debt Securities [Member] | GSE debentures |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 1,478,777 |  | 1,334,549 |
Gross Unrealized Gain |  | 5,211 |  | 3,366 |
Gross Unrealized Loss |  | 1,615 |  | 8,988 |
Fair Value |  | 1,482,373 |  | 1,328,927 |
Debt Securities [Member] | Corporate bonds |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 859,644 |  | 836,153 |
Gross Unrealized Gain |  | 9,292 |  | 8,667 |
Gross Unrealized Loss |  | 8,881 |  | 23,105 |
Fair Value |  | 860,055 |  | 821,715 |
Debt Securities [Member] | Municipal bonds |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 68,277 |  | 68,551 |
Gross Unrealized Gain |  | 423 |  | 195 |
Gross Unrealized Loss |  | 1,502 |  | 2,563 |
Fair Value |  | 67,198 |  | 66,183 |
Debt Securities [Member] | Capital trust notes |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 48,291 |  | 48,278 |
Gross Unrealized Gain |  | 6,614 |  | 6,435 |
Gross Unrealized Loss |  | 4,983 |  | 5,422 |
Fair Value |  | 49,922 |  | 49,291 |
Debt Securities [Member] | Asset-backed Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost | [2] | 386,085 |  | 386,768 |
Gross Unrealized Gain | [2] | 346 |  | 784 |
Gross Unrealized Loss | [2] | 1,757 |  | 430 |
Fair Value | [2] | 384,674 |  | 387,122 |
Mortgage Backed Securities And Other Securities [Member] |  |  |  |  |
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |
Amortized Cost |  | 5,699,166 | [3] | 5,628,256 | [4]
Gross Unrealized Gain |  | 54,906 | [3] | 45,973 | [4]
Gross Unrealized Loss |  | 29,428 | [3] | 60,709 | [4]
Fair Value |  | $ 5,724,644 | [3] | $ 5,613,520 | [4]
[1] | Primarily consists of mutual funds that are CRA-qualified investments.
[2] | The underlying assets of the asset-backed securities are substantially guaranteed by the U.S. Government.
[3] | The amortized cost includes the non-credit portion of OTTI recorded in AOCL. At March 31, 2019, the non-credit portion of OTTI recorded in AOCL was $8.6 million before taxes.
[4] | The amortized cost includes the non-credit portion of OTTI recorded in AOCL. At December 31, 2018, the non-credit portion of OTTI recorded in AOCL was $8.6 million before taxes.

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