Loans, Changes in the Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Change in the Allowance for Unfunded Commitments
Balance at beginning of period	$ 24,000
Balance at end of period	25,000	$ 24,000
Allowance for Unfunded Commitments:
Change in the Allowance for Unfunded Commitments
Balance at beginning of period	24,400	24,900	$ 21,900
Provision for Other Credit Losses	(1,000)	(500)	(3,000)
Balance at end of period	$ 25,400	$ 24,400	$ 24,900