Fair Value of Financial Instruments Nonrecurring Basis (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016
Assets measured on nonrecurring basis
Losses on impaired loans charged through allowance for loan losses	$ 711	$ 1,146	$ 727	$ 955	$ 7,238	$ 5,837	$ 672	$ 350
Nonrecurring Basis
Assets measured on nonrecurring basis
Losses on impaired loans charged through allowance for loan losses									$ 200
Nonrecurring Basis | Significant Other Observable Inputs (Level 2)
Assets measured on nonrecurring basis
Impaired loans, aggregate outstanding principal balance	41,900								41,900
Impaired loans, fair value	$ 34,700								$ 34,700