Loans (Analysis of Impaired Loans) (Details) - Loans, Excluding Purchased Credit Impaired Loans [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 5,927,172		$ 5,927,172		$ 5,618,041
Recorded Investment of Loans Individually Measured for Specific Impairment	18,864		18,864		16,080
Recorded Investment	12,959		12,959		14,726
Unpaid Principal Balance	17,601		17,601		19,547
Related Allowance	2,705		2,705		653
Average Recorded Investment Impaired Loans	23,840	$ 24,401	21,253	$ 25,634
Interest Recognized on Impaired Loans	48	280	74	545
Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	2,410,385		2,410,385		2,257,168
Recorded Investment of Loans Individually Measured for Specific Impairment	7,036		7,036		5,524
Recorded Investment	3,320		3,320		690
Unpaid Principal Balance	6,570		6,570		718
Related Allowance	2,486		2,486		321
Average Recorded Investment Impaired Loans	12,859	9,231	10,414	9,662
Interest Recognized on Impaired Loans	20	8	33	15
Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	96,890		96,890		94,948
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0		0
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment Impaired Loans	0	0	0	1
Interest Recognized on Impaired Loans	0	0	0	0
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	169,484		169,484		172,150
Recorded Investment of Loans Individually Measured for Specific Impairment	688		688		1,286
Recorded Investment	89		89		314
Unpaid Principal Balance	108		108		339
Related Allowance	1		1		314
Average Recorded Investment Impaired Loans	676	4,180	879	3,502
Interest Recognized on Impaired Loans	(3)	11	3	24
Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	233,499		233,499		213,158
Recorded Investment of Loans Individually Measured for Specific Impairment	708		708		0
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment Impaired Loans	354	235	236	157
Interest Recognized on Impaired Loans	0	0	0	0
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,370,662		1,370,662		1,308,673
Recorded Investment of Loans Individually Measured for Specific Impairment	1,445		1,445		2,106
Recorded Investment	636		636		0
Unpaid Principal Balance	687		687		0
Related Allowance	100		100		0
Average Recorded Investment Impaired Loans	1,749	1,966	1,868	3,427
Interest Recognized on Impaired Loans	10	23	14	33
Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,019,219		1,019,219		940,261
Recorded Investment of Loans Individually Measured for Specific Impairment	5,227		5,227		6,055
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment Impaired Loans	5,102	6,567	5,420	7,326
Interest Recognized on Impaired Loans	0	235	0	468
Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	10,605		10,605		14,283
Recorded Investment of Loans Individually Measured for Specific Impairment	103		103		467
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Average Recorded Investment Impaired Loans	206	974	293	686
Interest Recognized on Impaired Loans	1	2	3	3
Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	117,302		117,302		119,813
Recorded Investment of Loans Individually Measured for Specific Impairment	562		562		562
Recorded Investment	0		0		335
Unpaid Principal Balance	0		0		335
Related Allowance	0		0		3
Average Recorded Investment Impaired Loans	562	893	562	595
Interest Recognized on Impaired Loans	0	0	0	0
Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	78,867		78,867		83,634
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0		0
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	104,896		104,896		81,671
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0		0
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Related Allowance	0		0		0
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	315,363		315,363		332,282
Recorded Investment of Loans Individually Measured for Specific Impairment	3,095		3,095		80
Recorded Investment	1,860		1,860		15
Unpaid Principal Balance	1,870		1,870		15
Related Allowance	118		118		15
Average Recorded Investment Impaired Loans	2,332	355	1,581	278
Interest Recognized on Impaired Loans	20	$ 1	21	$ 2
Impaired Loans With Recorded Allowance [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	5,905		5,905		1,354
Unpaid Principal Balance	9,235		9,235		1,407
Impaired Loans Without Recorded Allowance [Member] | Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	3,716		3,716		4,834
Unpaid Principal Balance	5,337		5,337		6,455
Impaired Loans Without Recorded Allowance [Member] | Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Impaired Loans Without Recorded Allowance [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	599		599		972
Unpaid Principal Balance	1,011		1,011		1,397
Impaired Loans Without Recorded Allowance [Member] | Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	708		708		0
Unpaid Principal Balance	687		687		0
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	809		809		2,106
Unpaid Principal Balance	918		918		2,311
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	5,227		5,227		6,055
Unpaid Principal Balance	7,664		7,664		8,528
Impaired Loans Without Recorded Allowance [Member] | Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	103		103		467
Unpaid Principal Balance	103		103		490
Impaired Loans Without Recorded Allowance [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	562		562		227
Unpaid Principal Balance	562		562		227
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0		0
Unpaid Principal Balance	0		0		0
Impaired Loans Without Recorded Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	1,235		1,235		65
Unpaid Principal Balance	$ 1,319		$ 1,319		$ 139