Loans (Analysis of the Aged Loan Portfolio) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	$ 54,842
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	2,949
Commercial business: Secured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	35,504
Commercial business: Unsecured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	9
Real estate: One-to-four family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	1,158
Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	2,261
Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	9,922
Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	318
Real estate construction: One-to-four family residential: Residential construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	0
Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual Loans	2,721
Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	8,218,651	$ 8,163,583
Total Past Due	28,258	16,215
Nonaccrual Loans	54,842	66,189
Loans Receivable, Net	8,301,751	8,245,987
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	194,912	293,028
Total Past Due	0	0
Nonaccrual Loans	0	0
Loans Receivable, Net	194,912	293,028
Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	314,008	325,928
Total Past Due	1,258	2,148
Nonaccrual Loans	2,949	4,149
Loans Receivable, Net	318,215	332,225
Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Secured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	3,267,709	3,185,321
Total Past Due	9,488	4,930
Nonaccrual Loans	35,504	45,410
Loans Receivable, Net	3,312,701	3,235,661
Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Unsecured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	111,868	123,524
Total Past Due	240	601
Nonaccrual Loans	9	50
Loans Receivable, Net	112,117	124,175
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: One-to-four family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	233,941	184,256
Total Past Due	927	1,513
Nonaccrual Loans	1,158	785
Loans Receivable, Net	236,026	186,554
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	283,416	292,680
Total Past Due	0	673
Nonaccrual Loans	2,261	2,628
Loans Receivable, Net	285,677	295,981
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,606,085	1,590,004
Total Past Due	1,744	2,953
Nonaccrual Loans	9,922	7,029
Loans Receivable, Net	1,617,751	1,599,986
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	4,099	9,882
Total Past Due	0	0
Nonaccrual Loans	318	25
Loans Receivable, Net	4,417	9,907
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Residential construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	212,303	187,862
Total Past Due	93	0
Nonaccrual Loans	0	1,829
Loans Receivable, Net	212,396	189,691
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	1,910,505	1,898,655
Total Past Due	7,250	3,397
Nonaccrual Loans	2,721	4,284
Loans Receivable, Net	1,920,476	1,906,336
Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Current Loans	79,805	72,443
Total Past Due	7,258	0
Nonaccrual Loans	0	0
Loans Receivable, Net	87,063	72,443
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	21,959	10,190
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,057	1,446
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Secured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,864	2,530
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Unsecured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	240	100
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: One-to-four family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	694	1,111
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	92
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	1,744	2,485
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Residential construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	93	0
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	5,009	2,426
Financing Receivables, 30 to 59 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	7,258	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	6,299	5,444
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	201	702
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Secured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	3,624	2,400
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Unsecured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	501
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: One-to-four family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	233	402
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	468
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Residential construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	2,241	971
Financing Receivables, 60 to 89 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
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]
Total Past Due	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Secured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Commercial business: Unsecured loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: One-to-four family residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamily residential: Commercial land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	581
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Land and acquisition [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: One-to-four family residential: Residential construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate: Commercial and multifamiIy residential: Income property [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	0	0
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Loans, Excluding Purchased Credit Impaired Loans [Member] | Real estate construction: Commercial and multifamily residential: Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Past Due	$ 0	$ 0