Noninterest Income Gains and Losses on Derivatives (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gains and Losses on Derivatives [Abstract]
Gains and Losses on Exercised Warrant Assets	$ 48,275	$ 31,197	$ 41,455
Losses on Terminated Equity Warrant Assets	(4,422)	(3,015)	(1,040)
Unrealized Gain (Loss) on Derivatives	10,702	9,710	30,548
Gains on derivative instruments, net	$ 54,555	$ 37,892	$ 70,963