Loans (Analysis of Impaired Loans) (Details) - Loans, Excluding Purchased Credit Impaired Loans [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	$ 5,675,267		$ 5,618,041
Recorded Investment of Loans Individually Measured for Specific Impairment	28,815		16,080
Recorded Investment	16,939		14,726
Unpaid Principal Balance	25,584		19,547
Related Allowance	2,515		653
Average Recorded Investment Impaired Loans	22,448	$ 27,596
Interest Recognized on Impaired Loans	36	267
Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	2,285,351		2,257,168
Recorded Investment of Loans Individually Measured for Specific Impairment	18,681		5,524
Recorded Investment	11,861		690
Unpaid Principal Balance	11,996		718
Related Allowance	2,500		321
Average Recorded Investment Impaired Loans	12,103	10,698
Interest Recognized on Impaired Loans	17	7
Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	92,576		94,948
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	0	1
Interest Recognized on Impaired Loans	0	0
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	171,660		172,150
Recorded Investment of Loans Individually Measured for Specific Impairment	664		1,286
Recorded Investment	0		314
Unpaid Principal Balance	0		339
Related Allowance	0		314
Average Recorded Investment Impaired Loans	975	3,162
Interest Recognized on Impaired Loans	6	13
Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	219,163		213,158
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	0	235
Interest Recognized on Impaired Loans	0	0
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	1,322,410		1,308,673
Recorded Investment of Loans Individually Measured for Specific Impairment	2,053		2,106
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	2,080	4,168
Interest Recognized on Impaired Loans	3	10
Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	951,216		940,261
Recorded Investment of Loans Individually Measured for Specific Impairment	4,978		6,055
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	5,516	7,938
Interest Recognized on Impaired Loans	7	234
Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	12,810		14,283
Recorded Investment of Loans Individually Measured for Specific Impairment	310		467
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Average Recorded Investment Impaired Loans	388	544
Interest Recognized on Impaired Loans	1	1
Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	119,126		119,813
Recorded Investment of Loans Individually Measured for Specific Impairment	562		562
Recorded Investment	0		335
Unpaid Principal Balance	0		335
Related Allowance	0		3
Average Recorded Investment Impaired Loans	562	446
Interest Recognized on Impaired Loans	0	0
Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	86,584		83,634
Recorded Investment of Loans Individually Measured for Specific Impairment	0		0
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Related Allowance	0		0
Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	94,743		81,671
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 Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment of Loans Collectively Measured for Contingency Provision	319,628		332,282
Recorded Investment of Loans Individually Measured for Specific Impairment	1,567		80
Recorded Investment	15		15
Unpaid Principal Balance	15		15
Related Allowance	15		15
Average Recorded Investment Impaired Loans	824	404
Interest Recognized on Impaired Loans	2	$ 2
Impaired Loans With Recorded Allowance [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	11,876		1,354
Unpaid Principal Balance	12,011		1,407
Impaired Loans Without Recorded Allowance [Member] | Secured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	6,820		4,834
Unpaid Principal Balance	12,314		6,455
Impaired Loans Without Recorded Allowance [Member] | Unsecured Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	664		972
Unpaid Principal Balance	1,093		1,397
Impaired Loans Without Recorded Allowance [Member] | Commercial Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	2,053		2,106
Unpaid Principal Balance	2,257		2,311
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	4,978		6,055
Unpaid Principal Balance	7,390		8,528
Impaired Loans Without Recorded Allowance [Member] | Land And Acquisition [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	310		467
Unpaid Principal Balance	334		490
Impaired Loans Without Recorded Allowance [Member] | Residential Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	562		227
Unpaid Principal Balance	562		227
Impaired Loans Without Recorded Allowance [Member] | Income Property Multifamily Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | Owner Occupied Construction [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	0		0
Unpaid Principal Balance	0		0
Impaired Loans Without Recorded Allowance [Member] | Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment [Line Items]
Recorded Investment	1,552		65
Unpaid Principal Balance	$ 1,634		$ 139