Loans - Other (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) item	Dec. 31, 2014 USD ($)
Loans and Leases Receivable, Other Information [Abstract]
Number of types of loans | item	3
Net deferred loan origination fees and unamortized premium and discount	$ 19,800	$ 10,300
Non-accretable discount on acquired credit impaired loans	13,400	1,400
Accrued interest receivable on loans	7,300	4,500
Consumer and other [Member]
Loans and Leases Receivable, Other Information [Abstract]
Deposit Liabilities Reclassified as Loans Receivable	$ 560	51
Loans		$ 95
Reserved Based Energy Loans [Member]
Loans and Leases Receivable, Other Information [Abstract]
Percentage of total funded loans	4.20%	8.70%
Energy Related Service Industry Loans [Member]
Loans and Leases Receivable, Other Information [Abstract]
Percentage of total funded loans	5.20%	5.20%