Loans and Allowance for Loan Losses (Details 3) - Acquired loans - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Credit impaired
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Contractual principal and interest	$ 1,025,557	$ 1,337,703	$ 1,416,207
Non-accretable difference	(52,463)	(104,110)	(161,465)
Cash flows expected to be collected	973,094	1,233,593	1,254,742
Accretable Yield	(200,014)	(306,826)	(266,218)
Total acquired loans	773,080	926,767	988,524
Allowance for loan losses on acquired loans	(4,474)	(7,365)	(8,032)
Non-Credit impaired
Contractual loan payments receivable, estimates of amounts not expected to be collected, other fair value adjustments and the resulting fair values of acquired loans
Total acquired loans	$ 1,107,440	$ 1,327,999	$ 1,377,343