Related Parties Related Parties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loans and Leases Receivable, Related Parties [Roll Forward]
Lease payments on office space in facilities owned by related party afffiliates	$ 25,200	$ 25,000	$ 23,500
Directors and Senior Management [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Beginning balance	103,395	88,691
Advances	3,582,384	712,413
Payments	(3,104,004)	(698,149)
Adjustments	12,450	440
Ending balance	594,225	103,395	88,691
Board of Directors Chairman [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Lease payments on office space in facilities owned by related party afffiliates	$ 975	$ 1,100	$ 952
Executive Officer [Member]
Loans and Leases Receivable, Related Parties [Roll Forward]
Percentage of investment funds' assets held by clients	99.00%
Assets Held in Cavanal Hill Funds	$ 4,100,000