Summary of Portfolio of Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 301,088	[1]	$ 408,708	[2]
Gross Unrealized Gain	12,462	[1]	27,786	[2]
Gross Unrealized Loss	7,847	[1]	7,228	[2]
Fair Value	305,703	[1]	429,266	[2]
Mortgage-Related Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	99,784		165,000
Gross Unrealized Gain	2,150		12,261
Gross Unrealized Loss	756		6
Fair Value	101,178		177,255
Mortgage-Related Securities | GSE certificates
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	25,345	[3]	85,488
Gross Unrealized Gain	1,378	[3]	7,197
Gross Unrealized Loss	3	[3]	6
Fair Value	26,720	[3]	92,679
Mortgage-Related Securities | GSE CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	62,122	[4]	62,236
Gross Unrealized Gain	772	[4]	4,924
Gross Unrealized Loss	691	[4]
Fair Value	62,203	[4]	67,160
Mortgage-Related Securities | Private label CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	12,317		17,276
Gross Unrealized Gain			140
Gross Unrealized Loss	62
Fair Value	12,255		17,416
Other Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	201,304		243,708
Gross Unrealized Gain	10,312		15,525
Gross Unrealized Loss	7,091		7,222
Fair Value	204,525		252,011
Other Securities | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,079		46,288
Gross Unrealized Gain	86		128
Gross Unrealized Loss			120
Fair Value	1,165		46,296
Other Securities | Capital trust notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,275		35,231
Gross Unrealized Gain	5,530		7,363
Gross Unrealized Loss	2,003		4,159
Fair Value	35,802		38,435
Other Securities | Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	118,206		118,205
Gross Unrealized Gain	1,364		6,843
Gross Unrealized Loss	4,339		30
Fair Value	115,231		125,018
Other Securities | Common stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,744		43,984
Gross Unrealized Gain	3,332		1,191
Gross Unrealized Loss	749		2,913
Fair Value	$ 52,327		$ 42,262

[1] At September 30, 2013, the non-credit portion of OTTI recorded in AOCL was $570,000 (before taxes).

[2] At December 31, 2012, the non-credit portion of OTTI recorded in AOCL was $570,000 (before taxes).

[3] Government-sponsored enterprise

[4] Collateralized mortgage obligations