Business Combinations (Narrative) (Details) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended	3 Months Ended				6 Months Ended				0 Months Ended				3 Months Ended	6 Months Ended
	Jun. 30, 2013 operating_location	Jun. 30, 2012	Jun. 30, 2013 operating_location	Jun. 30, 2012	Dec. 31, 2012	Jun. 30, 2013 Financial Pacific Holding Corp [Member]		Jun. 30, 2012 Financial Pacific Holding Corp [Member]		Jun. 30, 2013 Financial Pacific Holding Corp [Member]		Jun. 30, 2012 Financial Pacific Holding Corp [Member]		Jul. 02, 2013 Financial Pacific Holding Corp [Member] Subsequent Event [Member]	Jul. 02, 2013 Financial Pacific Holding Corp [Member] Subsequent Event [Member] Minimum [Member]	Jul. 02, 2013 Financial Pacific Holding Corp [Member] Subsequent Event [Member] Maximum [Member]	Nov. 14, 2012 Circle Bancorp [Member]	Jun. 30, 2013 Circle Bancorp [Member] operating_location	Jun. 30, 2013 Circle Bancorp [Member] operating_location
Business Acquisition [Line Items]
Aggregate consideration to acquire entity														$ 158,000,000
Cash consideration to acquire entity														156,110,000			24,860,000
Equity consideration to acquire entity														1,900,000
Vesting period of equity consideration															2 years	3 years
Tax deductible goodwill														0
Merger related expenses	810,000	153,000	2,341,000	253,000		654,000				796,000								58,000	949,000
Number of locations in operation	205		205															6	6
Goodwill														89,312,000			12,597,000
Revenues																		4,000,000	9,100,000
Non-interest expense	87,931,000	86,936,000	173,693,000	174,632,000		3,435,000	[1]	3,754,000	[2]	6,997,000	[3]	7,353,000	[4]					1,200,000	3,900,000
Net income (loss)	$ 26,253,000	$ 23,277,000	$ 49,614,000	$ 48,780,000	$ 101,891,000	$ 5,485,000	[1]	$ 3,896,000	[2]	$ 9,464,000	[3]	$ 7,267,000	[4]					$ 1,600,000	$ 2,900,000

[1] FinPac amounts represent results from April 1, 2013 to June 30, 2013. Acquisition date is July 1, 2013.

[2] FinPac amounts represent results from April 1, 2012 to June 30, 2012. Acquisition date is July 1, 2013.

[3] FinPac amounts represent results from January 1, 2013 to June 30, 2013. Acquisition date is July 1, 2013.

[4] FinPac amounts represent results from January 1, 2012 to June 30, 2012. Acquisition date is July 1, 2013.