Noninterest Income Foreign Exchange Fees (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gains and Losses on Derivatives [Abstract]
Brokerage Commissions Revenue	$ 104,344	$ 89,354	$ 80,564
Forward Contract Commissions	10,934	14,004	6,414
Option Premium Fees	482	825	29
Foreign exchange fees	$ 115,760	$ 104,183	$ 87,007