Commitments and Contingencies Commitments and Contingencies (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Loan commitments to extend credit	$ 2,111,637	$ 1,921,067
Standby letters of credit	104,693	88,495
Commitments to purchase equipment being acquired for lease to others	1,257	12,839
Total	$ 2,217,587	$ 2,022,401