Loans and Allowance for Credit Losses - TDRs and pre and post-modification recorded investment (Details 8) - Loans Receivable $ in Thousands	Jun. 30, 2016 USD ($) Contract	Dec. 31, 2015 USD ($) Contract
Additional information on troubled debt restructurings
Number of Contracts | Contract	418	413
Pre-Modification Outstanding Recorded Investment	$ 78,058	$ 88,015
Post-Modification Outstanding Recorded Investment	$ 76,640	$ 86,588
Home equity lines of credit
Additional information on troubled debt restructurings
Number of Contracts | Contract	2	2
Pre-Modification Outstanding Recorded Investment	$ 101	$ 167
Post-Modification Outstanding Recorded Investment	$ 101	$ 167
Indirect auto
Additional information on troubled debt restructurings
Number of Contracts | Contract	56	49
Pre-Modification Outstanding Recorded Investment	$ 937	$ 749
Post-Modification Outstanding Recorded Investment	$ 937	$ 749
Commercial
Additional information on troubled debt restructurings
Number of Contracts | Contract	115	123
Pre-Modification Outstanding Recorded Investment	$ 51,130	$ 61,987
Post-Modification Outstanding Recorded Investment	$ 50,392	$ 61,173
Commercial | Owner occupied commercial real estate
Additional information on troubled debt restructurings
Number of Contracts | Contract	56	54
Pre-Modification Outstanding Recorded Investment	$ 26,515	$ 32,544
Post-Modification Outstanding Recorded Investment	$ 26,025	$ 32,058
Commercial | Income producing commercial real estate
Additional information on troubled debt restructurings
Number of Contracts | Contract	30	29
Pre-Modification Outstanding Recorded Investment	$ 20,713	$ 15,703
Post-Modification Outstanding Recorded Investment	$ 20,713	$ 15,629
Commercial | Construction
Additional information on troubled debt restructurings
Number of Contracts | Contract	8	14
Pre-Modification Outstanding Recorded Investment	$ 1,654	$ 10,785
Post-Modification Outstanding Recorded Investment	$ 1,485	$ 10,616
Commercial | Commercial & industrial
Additional information on troubled debt restructurings
Number of Contracts | Contract	21	26
Pre-Modification Outstanding Recorded Investment	$ 2,248	$ 2,955
Post-Modification Outstanding Recorded Investment	$ 2,169	$ 2,870
Residential | Residential mortgage
Additional information on troubled debt restructurings
Number of Contracts | Contract	179	173
Pre-Modification Outstanding Recorded Investment	$ 19,743	$ 19,101
Post-Modification Outstanding Recorded Investment	$ 19,468	$ 18,836
Residential | Construction
Additional information on troubled debt restructurings
Number of Contracts | Contract	47	44
Pre-Modification Outstanding Recorded Investment	$ 5,812	$ 5,663
Post-Modification Outstanding Recorded Investment	$ 5,427	$ 5,334
Consumer installment
Additional information on troubled debt restructurings
Number of Contracts | Contract	19	22
Pre-Modification Outstanding Recorded Investment	$ 335	$ 348
Post-Modification Outstanding Recorded Investment	$ 315	$ 329