Loans and Loans Held for Sale - Summary of Restructured Loans (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Restructured loans	[1]	$ 2,665	$ 8,193	$ 3,103	$ 10,771
Performing TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				15,080		$ 13,423
Performing TDRs | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Restructured loans				2,672		2,994
Performing TDRs | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				3,324		1,387
Performing TDRs | Commercial Construction
Financing Receivable, Modifications [Line Items]
Restructured loans				2,953		2,966
Performing TDRs | Residential Mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				2,235		2,375
Performing TDRs | Home Equity Loan
Financing Receivable, Modifications [Line Items]
Restructured loans				3,866		3,683
Performing TDRs | Installment And Other Consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				30		18
Nonperforming TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				10,105		11,598
Nonperforming TDRs | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Restructured loans				704		646
Nonperforming TDRs | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				3,944		4,493
Nonperforming TDRs | Commercial Construction
Financing Receivable, Modifications [Line Items]
Restructured loans				423		430
Nonperforming TDRs | Residential Mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				4,111		5,068
Nonperforming TDRs | Home Equity Loan
Financing Receivable, Modifications [Line Items]
Restructured loans				918		954
Nonperforming TDRs | Installment And Other Consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				5		7
Total TDRs
Financing Receivable, Modifications [Line Items]
Restructured loans				25,185		25,021
Total TDRs | Commercial Real Estate
Financing Receivable, Modifications [Line Items]
Restructured loans				3,376		3,640
Total TDRs | Commercial and Industrial
Financing Receivable, Modifications [Line Items]
Restructured loans				7,268		5,880
Total TDRs | Commercial Construction
Financing Receivable, Modifications [Line Items]
Restructured loans				3,376		3,396
Total TDRs | Residential Mortgage
Financing Receivable, Modifications [Line Items]
Restructured loans				6,346		7,443
Total TDRs | Home Equity Loan
Financing Receivable, Modifications [Line Items]
Restructured loans				4,784		4,637
Total TDRs | Installment And Other Consumer
Financing Receivable, Modifications [Line Items]
Restructured loans				$ 35		$ 25

[1] Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.