Allowance for Loan and Lease Losses and Unfunded Commitments and Letters of Credit (Allowance for Loan and Lease Losses) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 75,646	$ 70,043
Charged-offs	(4,307)	(3,815)
Recoveries	2,636	2,018
Provision for loan and lease losses	5,852	2,775
Ending balance	79,827	71,021
Specific Reserve	5,857	94
General Allocation	73,970	70,927
Secured Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	29,341	36,050
Charged-offs	(2,414)	(1,109)
Recoveries	553	297
Provision for loan and lease losses	9,851	434
Ending balance	37,331	35,672
Specific Reserve	5,657	0
General Allocation	31,674	35,672
Unsecured Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	2,000	960
Charged-offs	(63)	(18)
Recoveries	249	68
Provision for loan and lease losses	409	178
Ending balance	2,595	1,188
Specific Reserve	2	0
General Allocation	2,593	1,188
One-to-Four Family Residential [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	701	599
Charged-offs	0	(307)
Recoveries	172	117
Provision for loan and lease losses	(315)	236
Ending balance	558	645
Specific Reserve	22	11
General Allocation	536	634
Commercial Land [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,265	1,797
Charged-offs	0	0
Recoveries	6	0
Provision for loan and lease losses	(526)	491
Ending balance	3,745	2,288
Specific Reserve	0	0
General Allocation	3,745	2,288
Income Property Multifamily [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,672	7,342
Charged-offs	(223)	0
Recoveries	141	35
Provision for loan and lease losses	(888)	(574)
Ending balance	4,702	6,803
Specific Reserve	0	26
General Allocation	4,702	6,777
Owner Occupied [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,459	6,439
Charged-offs	0	0
Recoveries	12	43
Provision for loan and lease losses	(722)	52
Ending balance	4,749	6,534
Specific Reserve	5	0
General Allocation	4,744	6,534
Land And Acquisition [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	963	316
Charged-offs	0	(14)
Recoveries	16	20
Provision for loan and lease losses	(67)	187
Ending balance	912	509
Specific Reserve	0	0
General Allocation	912	509
Residential Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	3,709	669
Charged-offs	0	0
Recoveries	3	9
Provision for loan and lease losses	924	431
Ending balance	4,636	1,109
Specific Reserve	0	0
General Allocation	4,636	1,109
Income Property Multifamily Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	7,053	404
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	421	378
Ending balance	7,474	782
Specific Reserve	0	0
General Allocation	7,474	782
Owner Occupied Construction [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	4,413	1,192
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	(2,490)	576
Ending balance	1,923	1,768
Specific Reserve	0	0
General Allocation	1,923	1,768
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,163	3,534
Charged-offs	(264)	(428)
Recoveries	260	285
Provision for loan and lease losses	57	(31)
Ending balance	5,216	3,360
Specific Reserve	171	57
General Allocation	5,045	3,303
Purchased Credit Impaired Loans [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	6,907	10,515
Charged-offs	(1,343)	(1,939)
Recoveries	1,224	1,144
Provision for loan and lease losses	(1,123)	(325)
Ending balance	5,665	9,395
Specific Reserve	0	0
General Allocation	5,665	9,395
Unallocated Financing Receivables [Member]
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	0	226
Charged-offs	0	0
Recoveries	0	0
Provision for loan and lease losses	321	742
Ending balance	321	968
Specific Reserve	0	0
General Allocation	$ 321	$ 968