Loans Loans (Restructured Loans Past Due in Excess of 90 Days) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) Item	Dec. 31, 2016 USD ($) Item	Dec. 31, 2015 USD ($) Item
Financing Receivable, Modifications [Line Items]
Number Of Loans Restructured During The Last Year In Excess of 90 Days Past Due | Item	1	2	1
Dollar amount of loans previously restructured during the last year in excess of 90 days past due	$ 43,137	$ 3,230	$ 259
Restructured loans on non-accrual status at period end	58,484	44,863	536
Chare-offs of restrucured loans recognized in connection with restructuring	0	4,115	88
Charge-offs of restructured loans recognized on previously restructured loans	9,951	9,490	0
Proceeds from sale of restructured loans	0	30,470	0
Non Accrual Loans [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans on non-accrual status at period end	$ 53,622	$ 44,863	$ 536