Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Receivables [Abstract]
Provision for loan losses	$ 31,554,000	$ 4,251,000	$ 2,218,000	$ 2,351,000	$ 3,627,000	$ 1,956,000	$ 10,393,000	$ 4,867,000	$ 40,374,000	$ 20,843,000	$ 24,349,000
Impact of change in allowance methodology	1,400,000
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				32,848,000				37,752,000	32,848,000	37,752,000
Charge-offs	49,000,000								51,756,000	28,833,000
Recoveries									3,683,000	3,086,000
Provision	35,000,000								40,374,000	20,843,000
Allowance for loan losses, ending balance	25,149,000				32,848,000				25,149,000	32,848,000	37,752,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	1,397,000				4,101,000				1,397,000	4,101,000
Loans individually evaluated for impairment	33,554,000				77,896,000				33,554,000	77,896,000
Reserves for loans collectively evaluated for impairment	23,752,000				28,747,000				23,752,000	28,747,000
Loans collectively evaluated for impairment	1,274,818,000				1,372,143,000				1,274,818,000	1,372,143,000
Loans sold during period	43,000,000								319,200,000
Reserve for Off-balance Sheet Activities
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves	182,000				227,000				182,000	227,000
Reserve for Losses on Mortgage Loans Sold
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves	1,700,000				1,800,000				1,700,000	1,800,000	2,000,000
Charges against reserves									488,012	809,282	637,000
Provision expense									392,103	640,893	883,000
Real Estate Loans | Construction Loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				8,214,000				12,014,000	8,214,000	12,014,000
Charge-offs									17,825,000	11,391,000
Recoveries									1,138,000	2,010,000
Provision									12,742,000	5,581,000
Allowance for loan losses, ending balance	4,269,000				8,214,000				4,269,000	8,214,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	191,000				570,000				191,000	570,000
Loans individually evaluated for impairment	8,170,000				29,078,000				8,170,000	29,078,000
Reserves for loans collectively evaluated for impairment	4,078,000				7,644,000				4,078,000	7,644,000
Loans collectively evaluated for impairment	123,811,000				173,725,000				123,811,000	173,725,000
Real Estate Loans | Owner Occupied
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				5,792,000				5,958,000	5,792,000	5,958,000
Charge-offs									7,334,000	3,611,000
Recoveries									165,000	136,000
Provision									5,751,000	3,309,000
Allowance for loan losses, ending balance	4,374,000				5,792,000				4,374,000	5,792,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	189,000				585,000				189,000	585,000
Loans individually evaluated for impairment	11,524,000				24,045,000				11,524,000	24,045,000
Reserves for loans collectively evaluated for impairment	4,185,000				5,207,000				4,185,000	5,207,000
Loans collectively evaluated for impairment	331,438,000				324,886,000				331,438,000	324,886,000
Real Estate Loans | Non-owner Occupied
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				4,668,000				7,150,000	4,668,000	7,150,000
Charge-offs									9,830,000	4,014,000
Recoveries									664,000	53,000
Provision									8,433,000	1,479,000
Allowance for loan losses, ending balance	3,935,000				4,668,000				3,935,000	4,668,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	89,000				143,000				89,000	143,000
Loans individually evaluated for impairment	5,537,000				9,614,000				5,537,000	9,614,000
Reserves for loans collectively evaluated for impairment	3,846,000				4,525,000				3,846,000	4,525,000
Loans collectively evaluated for impairment	205,952,000				233,213,000				205,952,000	233,213,000
Real Estate Loans | One to Four Family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				3,726,000				3,706,000	3,726,000	3,706,000
Charge-offs									3,512,000	2,509,000
Recoveries									215,000	174,000
Provision									2,762,000	2,355,000
Allowance for loan losses, ending balance	3,191,000				3,726,000				3,191,000	3,726,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	0				45,000				0	45,000
Loans individually evaluated for impairment	1,435,000				4,341,000				1,435,000	4,341,000
Reserves for loans collectively evaluated for impairment	3,191,000				3,681,000				3,191,000	3,681,000
Loans collectively evaluated for impairment	167,176,000				174,706,000				167,176,000	174,706,000
Real Estate Loans | Multifamily
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				805,000				424,000	805,000	424,000
Charge-offs									347,000	11,000
Recoveries									0	0
Provision									136,000	392,000
Allowance for loan losses, ending balance	594,000				805,000				594,000	805,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	0				135,000				0	135,000
Loans individually evaluated for impairment	530,000				595,000				530,000	595,000
Reserves for loans collectively evaluated for impairment	594,000				670,000				594,000	670,000
Loans collectively evaluated for impairment	34,807,000				39,286,000				34,807,000	39,286,000
Real Estate Loans | Home Equity Lines of Credit
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				3,310,000				3,298,000	3,310,000	3,298,000
Charge-offs									4,360,000	3,151,000
Recoveries									186,000	106,000
Provision									4,686,000	3,057,000
Allowance for loan losses, ending balance	3,822,000				3,310,000				3,822,000	3,310,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	0				112,000				0	112,000
Loans individually evaluated for impairment	705,000				928,000				705,000	928,000
Reserves for loans collectively evaluated for impairment	3,822,000				3,198,000				3,822,000	3,198,000
Loans collectively evaluated for impairment	191,183,000				200,292,000				191,183,000	200,292,000
Commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				5,712,000				4,335,000	5,712,000	4,335,000
Charge-offs									7,796,000	3,494,000
Recoveries									956,000	423,000
Provision									5,419,000	4,448,000
Allowance for loan losses, ending balance	4,291,000				5,712,000				4,291,000	5,712,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	928,000				2,511,000				928,000	2,511,000
Loans individually evaluated for impairment	5,653,000				9,295,000				5,653,000	9,295,000
Reserves for loans collectively evaluated for impairment	3,363,000				3,201,000				3,363,000	3,201,000
Loans collectively evaluated for impairment	168,787,000				167,752,000				168,787,000	167,752,000
Consumer and other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, beginning balance				621,000				867,000	621,000	867,000
Charge-offs									752,000	652,000
Recoveries									359,000	184,000
Provision									445,000	222,000
Allowance for loan losses, ending balance	673,000				621,000				673,000	621,000
Financing Receivable, Allowance for Credit Loss, Additional Information
Reserves for loans individually evaluated for impairment	0				0				0	0
Loans individually evaluated for impairment	0				0				0	0
Reserves for loans collectively evaluated for impairment	673,000				621,000				673,000	621,000
Loans collectively evaluated for impairment	$ 51,664,000				$ 58,283,000				$ 51,664,000	$ 58,283,000