Loans (Analysis of Impaired Loans) (Details) (Loans, Excluding Purchased Credit Impaired Loans [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 5,186,695	$ 4,193,062
Recorded Investment of Loans Individually Measured for Specific Impairment	28,099	26,389
Recorded Investment	0	23
Unpaid Principal Balance	0	27
Related Allowance	0	4
Impaired Financing Receivable, Average Recorded Investment	26,635	32,039	47,524
Impaired Financing Receivable, Interest Income, Accrual Method	1,327	1,306	1,114
Income Property Multifamily Construction [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	73,783	86,521
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	0	0	3,169
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0
Consumer Portfolio Segment [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	344,908	328,167
Recorded Investment of Loans Individually Measured for Specific Impairment	124	167
Impaired Financing Receivable, Average Recorded Investment	147	253	1,112
Impaired Financing Receivable, Interest Income, Accrual Method	9	6	7
Land And Acquisition [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	16,401	9,726
Recorded Investment of Loans Individually Measured for Specific Impairment	109	1,944
Recorded Investment	109	113
Unpaid Principal Balance	109	113
Related Allowance	67	71
Impaired Financing Receivable, Average Recorded Investment	694	2,624	4,465
Impaired Financing Receivable, Interest Income, Accrual Method	6	6	0
Residential Construction [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	98,521	41,992
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	0	420	3,223
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	11
Commercial Land [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	189,779	142,719
Recorded Investment of Loans Individually Measured for Specific Impairment	0	115
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
Impaired Financing Receivable, Average Recorded Investment	82	1,691	3,124
Impaired Financing Receivable, Interest Income, Accrual Method	0	0	0
Income Property Multifamily [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,295,650	1,140,019
Recorded Investment of Loans Individually Measured for Specific Impairment	6,349	6,413
Recorded Investment	0	918
Unpaid Principal Balance	0	933
Related Allowance	0	26
Impaired Financing Receivable, Average Recorded Investment	6,782	8,910	7,895
Impaired Financing Receivable, Interest Income, Accrual Method	270	238	77
Owner Occupied [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	835,895	749,601
Recorded Investment of Loans Individually Measured for Specific Impairment	8,846	11,008
Recorded Investment	582	3,802
Unpaid Principal Balance	582	3,817
Related Allowance	27	1,073
Impaired Financing Receivable, Average Recorded Investment	9,472	10,779	13,315
Impaired Financing Receivable, Interest Income, Accrual Method	956	971	1,004
Owner Occupied Construction [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	58,944	38,916
Recorded Investment of Loans Individually Measured for Specific Impairment	0	0
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Related Allowance	0	0
One-to-Four Family Residential [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	169,619	104,272
Recorded Investment of Loans Individually Measured for Specific Impairment	2,145	1,620
Recorded Investment	424	442
Unpaid Principal Balance	465	479
Related Allowance	120	138
Impaired Financing Receivable, Average Recorded Investment	2,094	1,665	2,130
Impaired Financing Receivable, Interest Income, Accrual Method	49	63	0
Secured Loans [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	2,023,104	1,478,560
Recorded Investment of Loans Individually Measured for Specific Impairment	10,524	5,087
Recorded Investment	99	2,866
Unpaid Principal Balance	99	2,885
Related Allowance	25	343
Impaired Financing Receivable, Average Recorded Investment	7,345	5,636	8,978
Impaired Financing Receivable, Interest Income, Accrual Method	36	19	9
Unsecured Loans [Member]
Recorded Investment of Loans Collectively Measured for Contingency Provision	80,091	72,569
Recorded Investment of Loans Individually Measured for Specific Impairment	2	35
Recorded Investment	2	35
Unpaid Principal Balance	2	35
Related Allowance	2	35
Impaired Financing Receivable, Average Recorded Investment	19	61	113
Impaired Financing Receivable, Interest Income, Accrual Method	1	3	6
Impaired Loans Without Recorded Allowance [Member]
Recorded Investment	26,883	18,190
Unpaid Principal Balance	38,433	26,223
Impaired Loans With Recorded Allowance [Member]
Recorded Investment	1,216	8,199
Unpaid Principal Balance	1,257	8,289
Related Allowance	241	1,690
Impaired Loans Without Recorded Allowance [Member]
Recorded Investment	124	144
Unpaid Principal Balance	201	210
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily Construction [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | Land And Acquisition [Member]
Recorded Investment	0	1,831
Unpaid Principal Balance	0	2,587
Impaired Loans Without Recorded Allowance [Member] | Residential Construction [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | Commercial Land [Member]
Recorded Investment	0	115
Unpaid Principal Balance	0	398
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily [Member]
Recorded Investment	6,349	5,495
Unpaid Principal Balance	10,720	7,885
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied [Member]
Recorded Investment	8,264	7,206
Unpaid Principal Balance	12,732	10,464
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied Construction [Member]
Recorded Investment	0	0
Unpaid Principal Balance	0	0
Impaired Loans Without Recorded Allowance [Member] | One-to-Four Family Residential [Member]
Recorded Investment	1,721	1,178
Unpaid Principal Balance	2,370	2,119
Impaired Loans Without Recorded Allowance [Member] | Secured Loans [Member]
Recorded Investment	10,425	2,221
Unpaid Principal Balance	12,410	2,560
Impaired Loans Without Recorded Allowance [Member] | Unsecured Loans [Member]
Recorded Investment	0	0
Unpaid Principal Balance	$ 0	$ 0