Summary of Portfolio of Securities Available for Sale (Detail) (USD $) In Thousands	Jun. 30, 2011		Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 164,195	[1]	$ 645,034	[2]
Gross Unrealized Gain	6,634	[1]	31,841	[2]
Gross Unrealized Loss	8,557	[1]	23,919	[2]
Fair Value	162,272	[1]	652,956	[2]
Mortgage-related Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	81,224		468,976
Gross Unrealized Gain	1,735		16,641
Gross Unrealized Loss	324		437
Fair Value	82,635		485,180
Mortgage-related Securities | GSE certificates
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	47,369	[3]	203,480
Gross Unrealized Gain	1,735	[3]	8,067
Gross Unrealized Loss	20	[3]	32
Fair Value	49,084	[3]	211,515
Mortgage-related Securities | Private label CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	33,855	[4]	51,657
Gross Unrealized Gain			110
Gross Unrealized Loss	304	[4]	405
Fair Value	33,551	[4]	51,362
Mortgage-related Securities | GSE CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			213,839
Gross Unrealized Gain			8,464
Fair Value			222,303
Other Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	82,971		176,058
Gross Unrealized Gain	4,899		15,200
Gross Unrealized Loss	8,233		23,482
Fair Value	79,637		167,776
Other Securities | GSE debentures
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	618		620
Gross Unrealized Loss	10
Fair Value	608		620
Other Securities | State, County, and Municipal
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,309		1,304
Gross Unrealized Gain	55		41
Gross Unrealized Loss	2		11
Fair Value	1,362		1,334
Other Securities | Capital trust notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	38,842		38,843
Gross Unrealized Gain	2,880		8,550
Gross Unrealized Loss	4,376		5,389
Fair Value	37,346		42,004
Other Securities | Preferred Stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			30,574
Gross Unrealized Gain	455		2,129
Gross Unrealized Loss			11,964
Fair Value	455		20,739
Other Securities | Common Stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42,202		42,044
Gross Unrealized Gain	1,509		3,786
Gross Unrealized Loss	3,845		5,554
Fair Value	39,866		40,276
Other Securities | U.S. Treasury obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			57,859
Gross Unrealized Gain			694
Fair Value			58,553
Other Securities | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost			4,814
Gross Unrealized Loss			564
Fair Value			$ 4,250

[1] The non-credit portion of OTTI was $570,000 (before taxes).

[2] The non-credit portion of OTTI was $12.5 million (before taxes).

[3] Government-sponsored enterprises

[4] Collateralized mortgage obligations