Summary of Portfolio of Securities Available for Sale (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 305,040	[1]	$ 408,708	[2]
Gross Unrealized Gain	14,269	[1]	27,786	[2]
Gross Unrealized Loss	4,219	[1]	7,228	[2]
Fair Value	315,090	[1]	429,266	[2]
Mortgage-Related Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	103,473		165,000
Gross Unrealized Gain	2,513		12,261
Gross Unrealized Loss	97		6
Fair Value	105,889		177,255
Mortgage-Related Securities | GSE certificates
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,848	[3]	85,488
Gross Unrealized Gain	1,543	[3]	7,197
Gross Unrealized Loss	2	[3]	6
Fair Value	29,389	[3]	92,679
Mortgage-Related Securities | GSE CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	62,160	[4]	62,236
Gross Unrealized Gain	970	[4]	4,924
Fair Value	63,130	[4]	67,160
Mortgage-Related Securities | Private label CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	13,465		17,276
Gross Unrealized Gain			140
Gross Unrealized Loss	95
Fair Value	13,370		17,416
Other Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	201,567		243,708
Gross Unrealized Gain	11,756		15,525
Gross Unrealized Loss	4,122		7,222
Fair Value	209,201		252,011
Other Securities | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,077		46,288
Gross Unrealized Gain	103		128
Gross Unrealized Loss			120
Fair Value	1,180		46,296
Other Securities | Capital trust notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,666		35,231
Gross Unrealized Gain	4,471		7,363
Gross Unrealized Loss	2,478		4,159
Fair Value	34,659		38,435
Other Securities | Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	118,205		118,205
Gross Unrealized Gain	4,406		6,843
Gross Unrealized Loss	898		30
Fair Value	121,713		125,018
Other Securities | Common stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,619		43,984
Gross Unrealized Gain	2,776		1,191
Gross Unrealized Loss	746		2,913
Fair Value	$ 51,649		$ 42,262

[1] At June 30, 2013, the non-credit portion of OTTI recorded in accumulated other comprehensive loss ("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 enterprises

[4] Collateralized mortgage obligations