Loans and Allowance for Loan Losses - Past Due Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	$ 3,415,575	$ 3,166,911
Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	78,313	88,835
Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	7,174	8,101
30-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	10,994	15,063
90 Days or More and Accruing Interest
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	1,639	1,996
Financing Receivables Current
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	3,317,455	3,052,916
Commercial and Industrial
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	813,054	715,075
Commercial and Industrial | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	1,766	2,144
Commercial and Industrial | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	707	533
Commercial and Industrial | 30-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	3,138	5,859
Commercial and Industrial | 90 Days or More and Accruing Interest
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	145	90
Commercial and Industrial | Financing Receivables Current
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	807,298	706,449
Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	522,471	448,326
Construction | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	7,061	7,728
Construction | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	328	300
Construction | 30-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	850	1,412
Construction | 90 Days or More and Accruing Interest
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	193	241
Construction | Financing Receivables Current
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	514,039	438,645
Residential Real Estate | 1-to-4 Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	528,158	480,989
Residential Real Estate | 1-to-4 Family Mortgage | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	21,012	23,498
Residential Real Estate | 1-to-4 Family Mortgage | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	2,293	2,548
Residential Real Estate | Residential Line of Credit
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	208,668	194,986
Residential Real Estate | Residential Line of Credit | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	507	699
Residential Real Estate | Multi-Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	57,344	62,374
Residential Real Estate | Multi-Family Mortgage | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	16	20
Residential Real Estate | 30-89 Days Past Due | 1-to-4 Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	3,605	4,678
Residential Real Estate | 30-89 Days Past Due | Residential Line of Credit
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	1,345	527
Residential Real Estate | 90 Days or More and Accruing Interest | 1-to-4 Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	859	956
Residential Real Estate | 90 Days or More and Accruing Interest | Residential Line of Credit
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	254	134
Residential Real Estate | Financing Receivables Current | 1-to-4 Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	500,389	449,309
Residential Real Estate | Financing Receivables Current | Residential Line of Credit
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	206,562	193,626
Residential Real Estate | Financing Receivables Current | Multi-Family Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	57,328	62,354
Commercial Real Estate | Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	470,872	495,872
Commercial Real Estate | Owner Occupied | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	8,325	11,962
Commercial Real Estate | Owner Occupied | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	2,052	2,582
Commercial Real Estate | Non-Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	600,629	551,588
Commercial Real Estate | Non-Owner Occupied | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	18,049	18,164
Commercial Real Estate | Non-Owner Occupied | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	1,212	1,371
Commercial Real Estate | 30-89 Days Past Due | Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	249	521
Commercial Real Estate | 30-89 Days Past Due | Non-Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans		121
Commercial Real Estate | 90 Days or More and Accruing Interest | Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans		358
Commercial Real Estate | Financing Receivables Current | Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	460,246	480,449
Commercial Real Estate | Financing Receivables Current | Non-Owner Occupied
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	581,368	531,932
Consumer and Other
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	214,379	217,701
Consumer and Other | Purchased Credit Impaired
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	22,084	25,319
Consumer and Other | Non Accruing
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	75	68
Consumer and Other | 30-89 Days Past Due
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	1,807	1,945
Consumer and Other | 90 Days or More and Accruing Interest
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	188	217
Consumer and Other | Financing Receivables Current
Financing Receivable Recorded Investment Past Due [Line Items]
Loans	$ 190,225	$ 190,152