Loan Portfolio and Credit Quality TDR Loans Restructured or Defaulted in Period (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2016 USD ($) Loans		Jun. 30, 2015 USD ($) Loans		Jun. 30, 2016 USD ($) Loans		Jun. 30, 2015 USD ($) Loans		Dec. 31, 2015 USD ($)
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 30,400				$ 30,400				$ 30,600
Financing Receivable, Modifications, Number of Contracts | Loans	4		4		6		10
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 8,600		$ 5,547		$ 8,920		$ 5,929
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 8,601		$ 5,556		$ 8,746		$ 5,938
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Accruing Troubled Debt Restructured Loans [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Recorded Investment	$ 23,900				$ 23,900				$ 18,600
Commercial and industrial [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	2		1		3		1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 7,209		$ 1,298		$ 7,384		$ 1,298
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 7,209		$ 1,304		$ 7,209		$ 1,304
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial and industrial [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	2		0		2		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 7,209		$ 0		$ 7,209		$ 0
Commercial and industrial [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial and industrial [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial and industrial [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		1	[1]	1	[1]	1	[1]
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 1,304	[1]	$ 0	[1]	$ 1,304	[1]
Commercial real estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1		1		1		1
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 1,276		$ 4,118		$ 1,276		$ 4,118
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 1,276		$ 4,118		$ 1,276		$ 4,118
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial real estate [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		1		0		1
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 4,118		$ 0		$ 4,118
Commercial real estate [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial real estate [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Commercial real estate [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1	[1]	0		1	[1]	0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 1,276	[1]	$ 0		$ 1,276	[1]	$ 0
Construction and land [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Construction and land [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Construction and land [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Construction and land [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Construction and land [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Residential [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1		2		2		8
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 115		$ 131		$ 260		$ 513
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 116		$ 134		$ 261		$ 516
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Residential [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Residential [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	1		1		2		7
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 116		$ 109		$ 261		$ 491
Residential [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		1		0		1
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 25		$ 0		$ 25
Residential [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Home equity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Home equity [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Home equity [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Home equity [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Home equity [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Consumer and other [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Pre-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Subsequent Default, Recorded Investment	$ 0		$ 0		$ 0		$ 0
Consumer and other [Member] | Extension of Term [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Consumer and other [Member] | Temporary Rate Reduction [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Consumer and other [Member] | Payment Deferral [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0
Consumer and other [Member] | Combination of Concessions [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | Loans	0		0		0		0
Financing Receivable, Modifications, Post-Modification Recorded Investment	$ 0		$ 0		$ 0		$ 0

[1] Combination of concessions includes loans that have had more than one modification, including extension of term, temporary reduction of interest rate, and/or payment deferral.