Summary of Portfolio of Securities Available for Sale (Detail) (USD $)	Jun. 30, 2012		Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 402,089,000	[1]	$ 723,095,000	[2]
Gross Unrealized Gain	16,366,000	[1]	11,750,000	[2]
Gross Unrealized Loss	6,952,000	[1]	10,183,000	[2]
Fair Value	411,503,000	[1]	724,662,000	[2]
Mortgage-Related Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	175,199,000		185,321,000
Gross Unrealized Gain	10,893,000		7,916,000
Gross Unrealized Loss	634,000		1,275,000
Fair Value	185,458,000		191,962,000
Mortgage-Related Securities | GSE certificates
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	91,166,000	[3]	97,642,000
Gross Unrealized Gain	6,355,000	[3]	5,013,000
Gross Unrealized Loss	8,000	[3]	10,000
Fair Value	97,513,000	[3]	102,645,000
Mortgage-Related Securities | GSE CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	62,305,000	[4]	62,373,000
Gross Unrealized Gain	4,538,000	[4]	2,903,000
Fair Value	66,843,000	[4]	65,276,000
Mortgage-Related Securities | Private label CMOs
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	21,728,000		25,306,000
Gross Unrealized Loss	626,000		1,265,000
Fair Value	21,102,000		24,041,000
Other Securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	226,890,000		537,774,000
Gross Unrealized Gain	5,473,000		3,834,000
Gross Unrealized Loss	6,318,000		8,908,000
Fair Value	226,045,000		532,700,000
Other Securities | GSE debentures
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	97,388,000		456,969,000
Gross Unrealized Gain	399,000		1,797,000
Fair Value	97,787,000		458,766,000
Other Securities | State, county, and municipal
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,192,000		1,188,000
Gross Unrealized Gain	108,000		97,000
Fair Value	1,300,000		1,285,000
Other Securities | Capital trust notes
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	35,437,000		36,754,000
Gross Unrealized Gain	900,000		141,000
Gross Unrealized Loss	4,037,000		4,692,000
Fair Value	32,300,000		32,203,000
Other Securities | Preferred stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	49,890,000
Gross Unrealized Gain	2,888,000		195,000
Fair Value	52,778,000		195,000
Other Securities | Common stock
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	42,983,000		42,863,000
Gross Unrealized Gain	1,178,000		1,604,000
Gross Unrealized Loss	2,281,000		4,216,000
Fair Value	$ 41,880,000		$ 40,251,000

[1] The non-credit portion of OTTI recorded in accumulated other comprehensive loss ("AOCL") was $570,000 (before taxes).

[2] The non-credit portion of OTTI recorded in AOCL was $570,000 (before taxes).

[3] Government-sponsored enterprises

[4] Collateralized mortgage obligations