FAIR VALUE, Assets And Liabilities Measured At Fair Value On Recurring And Non-Recurring Basis (Details) (USD $)	3 Months Ended		6 Months Ended										3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended				3 Months Ended				6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 Fair Value, Measurements, Recurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2010 Fair Value, Measurements, Recurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Dec. 31, 2010 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 1 [Member]	Jun. 30, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Dec. 31, 2010 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 2 [Member]	Jun. 30, 2011 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2010 Fair Value, Measurements, Recurring [Member] Fair Value, Inputs, Level 3 [Member]	Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Estimate of Fair Value, Fair Value Disclosure [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 1 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 2 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Fair Value, Inputs, Level 3 [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Total Gains (Losses) [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Total Gains (Losses) [Member]		Jun. 30, 2011 Fair Value, Measurements, Nonrecurring [Member] Total Gains (Losses) [Member]		Jun. 30, 2010 Fair Value, Measurements, Nonrecurring [Member] Total Gains (Losses) [Member]
Investment securities available-for-sale [Abstract]
U.S. Treasury securities					$ 20,625,000	$ 20,454,000	$ 20,625,000	$ 20,454,000	$ 0	$ 0	$ 0	$ 0
U.S. Government agency and U.S. Government sponsored enterprise debt securities					1,205,620,000	1,333,465,000	0	0	1,205,620,000	1,333,465,000	0	0
U.S. Government agency and U.S. Government sponsored enterprise mortgage-backed securities [Abstract]
Commercial mortgage-backed securities					24,334,000	19,132,000	0	0	24,334,000	19,132,000	0	0
Residential mortgage-backed securities					765,298,000	306,714,000	0	0	765,298,000	306,714,000	0	0
Municipal securities					32,880,000	0	0	0	32,880,000	0	0	0
Other residential mortgage-backed securities [Abstract]
Investment grade					0	0	0	0	0	0	0	0
Non-investment grade					0	6,254,000	0	0	0	0	0	6,254,000
Corporate debt securities [Abstract]
Investment grade					1,121,835,000	1,056,867,000	0	0	1,121,835,000	1,056,867,000	0	0
Non-investment grade					16,497,000	38,730,000	0	0	14,044,000	35,957,000	2,453,000	2,773,000
Other securities					19,019,000	94,325,000	0	0	19,019,000	94,325,000	0	0
Total investment securities available-for-sale					3,206,108,000	2,875,941,000	20,625,000	20,454,000	3,183,030,000	2,846,460,000	2,453,000	9,027,000
Equity swap agreements					201,000	206,000	0	0	201,000	206,000	0	0
Foreign exchange options					4,932,000	5,084,000	0	0	4,932,000	5,084,000	0	0
Interest rate swaps					6,176,000	13,000	0	0	6,176,000	13,000	0	0
Derivative liabilities					(10,626,000)	(3,463,000)	0	0	(7,379,000)	(14,000)	(3,247,000)	(3,449,000)
Non-covered impaired loans [Abstract]
Total residential													3,898,000		11,892,000		5,540,000		15,622,000		0		0		0		0		0		0		0		0		3,898,000		11,892,000		5,540,000		15,622,000		(715,000)		(4,714,000)		(1,502,000)		(5,869,000)
Total commercial real estate													28,936,000		58,277,000		33,480,000		73,884,000		0		0		0		0		0		0		0		0		28,936,000		58,277,000		33,480,000		73,884,000		(16,933,000)		(15,427,000)		(20,708,000)		(27,614,000)
Total commercial and industrial													6,795,000		3,698,000		3,968,000		8,097,000		0		0		0		0		0		0		0		0		6,795,000		3,698,000		3,968,000		8,097,000		2,487,000		(3,158,000)		(4,562,000)		(6,549,000)
Total consumer													0		0		272,000		0		0		0		0		0		0		0		0		0		0		0		272,000		0		0		(350,000)		(178,000)		(432,000)
Total non-covered impaired loans													39,629,000		73,867,000		43,260,000		97,603,000		0		0		0		0		0		0		0		0		39,629,000		73,867,000		43,260,000		97,603,000		(15,161,000)		(23,649,000)		(26,950,000)		(40,464,000)
Mortgage servicing assets (single-family, multifamily and commercial)													13,772,000		18,233,000		13,772,000		18,233,000		0		0		0		0		0		0		0				13,772,000		18,233,000		13,772,000		18,233,000		(238,000)		(30,000)		(463,000)		(64,000)
Non-covered OREO			(16,500,000)										7,034,000		6,206,000		13,656,000		6,746,000		0		0		0		0		7,034,000		6,206,000		13,656,000		6,746,000		0		0		0		0		(460,000)		(666,000)		(1,512,000)		(2,913,000)
Covered OREO			(123,100,000)										46,333,000	[1]	42,676,000	[1]	93,097,000	[2]	55,374,000	[2]	0	[1]	0	[1]	0	[2]	0	[2]	46,333,000	[1]	42,676,000	[1]	93,097,000	[2]	55,374,000	[2]	0	[1]	0	[1]	0	[2]	0	[2]	(9,148,000)	[1]	(14,881,000)	[1]	(15,403,000)	[2]	(25,927,000)	[2]
Loans Held for Sale													0		0		11,493,000		2,456,000		0		0		0		0		0		0		0		0		0		0		11,493,000		2,456,000		0		0		(4,722,000)		(994,000)
FDIC percentage of reimbursement under shared loss agreements (in hundredths)	80.00%	80.00%	80.00%	80.00%
Percentage of company's liability for losses under shared loss agreements (in hundredths)	20.00%	20.00%	20.00%	20.00%
Company's liability for losses under shared loss agreements	1,800,000	3,000,000	3,100,000	5,200,000
Total eligible losses subject to shared loss agreements	$ 9,100,000	$ 14,900,000	$ 15,400,000	$ 25,900,000

[1] Covered OREO results from the WFIB and UCB FDIC-assisted acquisitions for which the Company entered into shared-loss agreements with the FDIC whereby the FDIC will reimburse the Company for 80% of eligible losses. As such, the Company's liability for losses is 20% of the $9.1 million in losses, or $1.8 million, and 20% of the $14.9 million in losses, or $3.0 million, for the three months ended June 30, 2011 and 2010, respectively.

[2] Covered OREO results from the WFIB and UCB FDIC-assisted acquisitions for which the Company entered into shared-loss agreements with the FDIC whereby the FDIC will reimburse the Company for 80% of eligible losses. As such, the Company's liability for losses is 20% of the $15.4 million in losses, or $3.1 million, and 20% of the $25.9 million in losses, or $5.2 million, for the six months ended June 30, 2011 and 2010, respectively.