Loans (Analysis of the Aged Loan Portfolio) (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	$ 69,504	$ 66,189
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	8,249,227	8,163,583
Past Due Loans	33,594	16,215
Nonaccrual Loans	69,504	66,189
Loans Receivable, Net	8,352,325	8,245,987
Secured Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	52,006	45,410
Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	3,342,422	3,185,321
Past Due Loans	12,991	4,930
Nonaccrual Loans	52,006	45,410
Loans Receivable, Net	3,407,419	3,235,661
Unsecured Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	30	50
Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	114,190	123,524
Past Due Loans	2,114	601
Nonaccrual Loans	30	50
Loans Receivable, Net	116,334	124,175
One-to-Four Family Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	976	785
One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	176,917	184,256
Past Due Loans	921	1,513
Nonaccrual Loans	976	785
Loans Receivable, Net	178,814	186,554
Commercial Land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	2,603	2,628
Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	279,067	292,680
Past Due Loans	0	673
Nonaccrual Loans	2,603	2,628
Loans Receivable, Net	281,670	295,981
Income Property Multifamily [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	1,552	4,284
Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,848,626	1,898,655
Past Due Loans	1,272	3,397
Nonaccrual Loans	1,552	4,284
Loans Receivable, Net	1,851,450	1,906,336
Owner Occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	6,963	7,029
Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,589,500	1,590,004
Past Due Loans	7,279	2,953
Nonaccrual Loans	6,963	7,029
Loans Receivable, Net	1,603,742	1,599,986
Land And Acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	318	25
Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	6,252	9,882
Past Due Loans	0	0
Nonaccrual Loans	318	25
Loans Receivable, Net	6,570	9,907
Residential Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	71	1,829
Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	197,359	187,862
Past Due Loans	1,243	0
Nonaccrual Loans	71	1,829
Loans Receivable, Net	198,673	189,691
Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	297,215	293,028
Past Due Loans	5,586	0
Nonaccrual Loans	0	0
Loans Receivable, Net	302,801	293,028
Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	79,694	72,443
Past Due Loans	0	0
Nonaccrual Loans	0	0
Loans Receivable, Net	79,694	72,443
Consumer Portfolio Segment [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	4,985	4,149
Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	317,985	325,928
Past Due Loans	2,188	2,148
Nonaccrual Loans	4,985	4,149
Loans Receivable, Net	325,158	332,225
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	5,651	5,444
Financing Receivables, 60 to 89 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	3,449	2,400
Financing Receivables, 60 to 89 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	492	501
Financing Receivables, 60 to 89 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	175	402
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	102	971
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	584	468
Financing Receivables, 60 to 89 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	849	702
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	27,943	10,190
Financing Receivables, 30 to 59 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	9,542	2,530
Financing Receivables, 30 to 59 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,622	100
Financing Receivables, 30 to 59 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	746	1,111
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	92
Financing Receivables, 30 to 59 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,170	2,426
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	6,695	2,485
Financing Receivables, 30 to 59 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,243	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	5,586	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	1,339	1,446
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Secured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Unsecured Loans [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | One-to-Four Family Residential [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Land [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Income Property Multifamily [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Owner Occupied [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Land And Acquisition [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Income Property Multifamily Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Owner Occupied Construction [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer Portfolio Segment [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Past Due Loans	$ 0	$ 0