Fair Value Measurements, Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3) (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2017	Dec. 31, 2016
Total investment securities available for sale
Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3)
Beginning Balance		$ 200	$ 200
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	[1]	(200)
Ending Balance		0	200
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Mortgage derivative loss		0	0
Derivative Financial Instruments
Assets and Liabilities Measured at Fair Value Using Significant Unobservable Inputs (Level 3)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers out of Level 3	[1]	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance		3,114	1,361
Mortgage derivative loss		(275)	1,753
Ending Balance		$ 2,839	$ 3,114

[1] (a) During the first quarter of 2017, the $200,000 level 3 investment security was transferred to level 2 based upon new pricing information.