Revenue from Contracts with Customers - Disaggregation of Revenue by Source (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 37,411	$ 34,283	$ 75,591	$ 67,809
Mortgage broker fees
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	288	414	567	730
Service charges on deposit accounts
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	9,151	8,696	18,008	16,961
Administrative services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,205	986	2,266	2,010
Card related fees
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,116	1,429	3,255	2,844
Other deposit related fees
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,034	2,853	5,892	5,211
Wealth management
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	22,617	19,905	45,603	40,053
Wealth management | Brokerage and insurance product commissions
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,784	5,449	11,815	11,669
Wealth management | Trust
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,226	3,237	6,643	6,545
Wealth management | Asset management
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 13,607	$ 11,219	$ 27,145	$ 21,839