Goodwill, Core Deposit Premium and Other Intangible Assets (Estimated future amortization expense for amortizable intangible assets) (Details) $ in Thousands	Jun. 30, 2016 USD ($)
Future amortization expense for amortizable intangible assets [Line Items]
Six months ending December 31, 2016	$ 8,107
Year ending December 31,
2017	11,948
2018	10,410
2019	8,827
2020	7,257
2021	5,730
Thereafter	8,588
Total	60,867
Core deposit intangibles
Future amortization expense for amortizable intangible assets [Line Items]
Six months ending December 31, 2016	2,460
Year ending December 31,
2017	4,419
2018	3,909
2019	3,426
2020	2,981
2021	2,463
Thereafter	5,214
Total	24,872
Mortgage servicing rights
Future amortization expense for amortizable intangible assets [Line Items]
Six months ending December 31, 2016	5,135
Year ending December 31,
2017	6,538
2018	5,604
2019	4,670
2020	3,736
2021	2,802
Thereafter	2,802
Total	31,287
Customer relationship intangible
Future amortization expense for amortizable intangible assets [Line Items]
Six months ending December 31, 2016	20
Year ending December 31,
2017	40
2018	39
2019	37
2020	37
2021	36
Thereafter	132
Total	341
Commercial servicing rights
Future amortization expense for amortizable intangible assets [Line Items]
Six months ending December 31, 2016	492
Year ending December 31,
2017	951
2018	858
2019	694
2020	503
2021	429
Thereafter	440
Total	$ 4,367