Loans (Analysis of Impaired Loans) (Details) - Loans, Excluding Purchased Credit Impaired Loans [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) Modifications	Dec. 31, 2014 USD ($) Modifications	Dec. 31, 2013 USD ($) Modifications
Financing Receivable, Modifications, Number of Contracts | Modifications	7	8	12
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 5,618,041	$ 5,186,695
Recorded Investment of Loans Individually Measured for Specific Impairment	16,080	28,099
Recorded Investment	15	0
Unpaid Principal Balance	15	0
Related Allowance	15	0
Impaired Financing Receivable, Average Recorded Investment	22,372	26,635	$ 32,039
Impaired Financing Receivable, Interest Income, Accrual Method	$ 202	$ 1,327	$ 1,306
Commercial business: Secured loans [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	5	4	2
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 2,257,168	$ 2,023,104
Recorded Investment of Loans Individually Measured for Specific Impairment	5,524	10,524
Recorded Investment	690	99
Unpaid Principal Balance	718	99
Related Allowance	321	25
Impaired Financing Receivable, Average Recorded Investment	7,987	7,345	$ 5,636
Impaired Financing Receivable, Interest Income, Accrual Method	84	36	19
Commercial business: Unsecured loans [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	94,948	80,091
Recorded Investment of Loans Individually Measured for Specific Impairment	0	2
Recorded Investment	0	2
Unpaid Principal Balance	0	2
Related Allowance	0	2
Impaired Financing Receivable, Average Recorded Investment	0	19	61
Impaired Financing Receivable, Interest Income, Accrual Method	$ 0	$ 1	$ 3
Real estate: One-to-four family residential [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	2	1
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 172,150	$ 169,619
Recorded Investment of Loans Individually Measured for Specific Impairment	1,286	2,145
Recorded Investment	314	424
Unpaid Principal Balance	339	465
Related Allowance	314	120
Impaired Financing Receivable, Average Recorded Investment	2,848	2,094	$ 1,665
Impaired Financing Receivable, Interest Income, Accrual Method	$ 47	$ 49	$ 63
Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	0	1
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 213,158	$ 189,779
Recorded Investment of Loans Individually Measured for Specific Impairment	0	0
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Impaired Financing Receivable, Average Recorded Investment	94	82	$ 1,691
Impaired Financing Receivable, Interest Income, Accrual Method	$ 0	$ 0	$ 0
Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	1	4
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 1,308,673	$ 1,295,650
Recorded Investment of Loans Individually Measured for Specific Impairment	2,106	6,349
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Impaired Financing Receivable, Average Recorded Investment	2,913	6,782	$ 8,910
Impaired Financing Receivable, Interest Income, Accrual Method	$ 36	$ 270	$ 238
Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	1	1
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 940,261	$ 835,895
Recorded Investment of Loans Individually Measured for Specific Impairment	6,055	8,846
Recorded Investment	0	582
Unpaid Principal Balance	0	582
Related Allowance	0	27
Impaired Financing Receivable, Average Recorded Investment	7,052	9,472	$ 10,779
Impaired Financing Receivable, Interest Income, Accrual Method	$ 26	$ 956	$ 971
Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	0	0	1
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 14,283	$ 16,401
Recorded Investment of Loans Individually Measured for Specific Impairment	467	109
Recorded Investment	0	109
Unpaid Principal Balance	0	109
Related Allowance	0	67
Impaired Financing Receivable, Average Recorded Investment	641	694	$ 2,624
Impaired Financing Receivable, Interest Income, Accrual Method	5	6	6
Real estate construction: One-to-four family residential: Residential construction [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	119,813	98,521
Recorded Investment of Loans Individually Measured for Specific Impairment	562	0
Recorded Investment	335	0
Unpaid Principal Balance	335	0
Related Allowance	3	0
Impaired Financing Receivable, Average Recorded Investment	648	0	420
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	$ 0
Real estate construction: Commercial and multifamily residential: Income property [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	83,634	73,783
Recorded Investment of Loans Individually Measured for Specific Impairment	0	0
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	81,671	58,944
Recorded Investment of Loans Individually Measured for Specific Impairment	0	0
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	$ 0	$ 0
Consumer [Member]
Financing Receivable, Modifications, Number of Contracts | Modifications	1	0	2
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 332,282	$ 344,908
Recorded Investment of Loans Individually Measured for Specific Impairment	80	124
Impaired Financing Receivable, Average Recorded Investment	189	147	$ 253
Impaired Financing Receivable, Interest Income, Accrual Method	4	9	$ 6
Impaired Loans Without Recorded Allowance [Member]
Recorded Investment	14,726	26,883
Unpaid Principal Balance	19,547	38,433
Impaired Loans With Recorded Allowance [Member]
Recorded Investment	1,354	1,216
Unpaid Principal Balance	1,407	1,257
Related Allowance	653	241
Impaired Loans Without Recorded Allowance [Member]
Recorded Investment	65	124
Unpaid Principal Balance	139	201
Impaired Loans Without Recorded Allowance [Member] | Commercial business: Secured loans [Member]
Recorded Investment	4,834	10,425
Unpaid Principal Balance	6,455	12,410
Impaired Loans Without Recorded Allowance [Member] | Commercial business: Unsecured loans [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | Real estate: One-to-four family residential [Member]
Recorded Investment	972	1,721
Unpaid Principal Balance	1,397	2,370
Impaired Loans Without Recorded Allowance [Member] | Real estate: Commercial and multifamily residential: Commercial land [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member]
Recorded Investment	2,106	6,349
Unpaid Principal Balance	2,311	10,720
Impaired Loans Without Recorded Allowance [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Recorded Investment	6,055	8,264
Unpaid Principal Balance	8,528	12,732
Impaired Loans Without Recorded Allowance [Member] | Real estate construction: One-to-four family residential: Land and acquisition [Member]
Recorded Investment	467	0
Unpaid Principal Balance	490	0
Impaired Loans Without Recorded Allowance [Member] | Real estate construction: One-to-four family residential: Residential construction [Member]
Recorded Investment	227	0
Unpaid Principal Balance	227	0
Impaired Loans Without Recorded Allowance [Member] | Real estate construction: Commercial and multifamily residential: Income property [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Recorded Investment	0	0
Unpaid Principal Balance	$ 0	$ 0