Noncovered Loans Receivable (Impaired Loans) (Details) (Noncovered Impaired Loans, USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	$ 6,293,000	$ 17,427,000
Recorded Investment With Specific Valuation Allowance	19,863,000	12,442,000
Total Recorded Investment	26,156,000	29,869,000
Unpaid Contractual Principal Balance	26,882,000	32,951,000
Related Specific Valuation Allowance	3,235,000	4,039,000
Government guarantee of originated impaired loans	2,400,000	2,900,000
Average Recorded Investment on Impaired Loans	30,768,000	31,373,000	32,982,000
Nonaccrual
Financing Receivable, Impaired [Line Items]
Interest income recognized on impaired loans	0	0		0
Restructured Performing
Financing Receivable, Impaired [Line Items]
Interest income recognized on impaired loans	1,200,000	1,100,000	1,000,000
Commercial Business
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	3,953,000	10,558,000
Recorded Investment With Specific Valuation Allowance	15,173,000	10,853,000
Total Recorded Investment	19,126,000	21,411,000
Unpaid Contractual Principal Balance	19,409,000	23,722,000
Related Specific Valuation Allowance	2,474,000	3,675,000
Average Recorded Investment on Impaired Loans	21,905,000	23,163,000	21,782,000
Real Estate Construction and Land Development
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	2,307,000	6,177,000
Recorded Investment With Specific Valuation Allowance	4,273,000	911,000
Total Recorded Investment	6,580,000	7,088,000
Unpaid Contractual Principal Balance	7,020,000	7,830,000
Related Specific Valuation Allowance	630,000	211,000
Average Recorded Investment on Impaired Loans	7,570,000	7,076,000	9,796,000
Consumer
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	33,000	100,000
Recorded Investment With Specific Valuation Allowance	172,000	678,000
Total Recorded Investment	205,000	778,000
Unpaid Contractual Principal Balance	208,000	780,000
Related Specific Valuation Allowance	56,000	153,000
Average Recorded Investment on Impaired Loans	779,000	254,000	427,000
Commercial and Industrial | Commercial Business
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	1,134,000	6,140,000
Recorded Investment With Specific Valuation Allowance	7,906,000	4,850,000
Total Recorded Investment	9,040,000	10,990,000
Unpaid Contractual Principal Balance	9,349,000	13,287,000
Related Specific Valuation Allowance	1,325,000	2,716,000
Average Recorded Investment on Impaired Loans	10,946,000	12,628,000	11,467,000
Owner-occupied Commercial Real Estate | Commercial Business
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	360,000	1,118,000
Recorded Investment With Specific Valuation Allowance	2,421,000	1,880,000
Total Recorded Investment	2,781,000	2,998,000
Unpaid Contractual Principal Balance	2,781,000	3,023,000
Related Specific Valuation Allowance	684,000	595,000
Average Recorded Investment on Impaired Loans	3,215,000	2,638,000	2,141,000
Non-owner Occupied Commercial Real Estate | Commercial Business
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	2,459,000	3,300,000
Recorded Investment With Specific Valuation Allowance	4,846,000	4,123,000
Total Recorded Investment	7,305,000	7,423,000
Unpaid Contractual Principal Balance	7,279,000	7,412,000
Related Specific Valuation Allowance	465,000	364,000
Average Recorded Investment on Impaired Loans	7,744,000	7,897,000	8,174,000
One-to-four Family Residential
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	0	592,000
Recorded Investment With Specific Valuation Allowance	245,000	0
Total Recorded Investment	245,000	592,000
Unpaid Contractual Principal Balance	245,000	619,000
Related Specific Valuation Allowance	75,000	0
Average Recorded Investment on Impaired Loans	514,000	880,000	977,000
One-to-four Family Residential | Real Estate Construction and Land Development
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	2,307,000	3,773,000
Recorded Investment With Specific Valuation Allowance	2,217,000	911,000
Total Recorded Investment	4,524,000	4,684,000
Unpaid Contractual Principal Balance	4,964,000	5,426,000
Related Specific Valuation Allowance	396,000	211,000
Average Recorded Investment on Impaired Loans	5,416,000	4,237,000	4,381,000
Five or More Family Residential and Commercial Properties | Real Estate Construction and Land Development
Financing Receivable, Impaired [Line Items]
Recorded Investment With No Specific Valuation Allowance	0	2,404,000
Recorded Investment With Specific Valuation Allowance	2,056,000	0
Total Recorded Investment	2,056,000	2,404,000
Unpaid Contractual Principal Balance	2,056,000	2,404,000
Related Specific Valuation Allowance	234,000	0
Average Recorded Investment on Impaired Loans	$ 2,154,000	$ 2,839,000	$ 5,415,000