Intangible Assets (Net Carrying Value) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Net carrying value of intangible assets
Goodwill	$ 1,137,166		$ 287,393
Loan servicing rights	51,393		11,122
Other intangible assets:
Total other intangible assets	35,700		26,982
Loan Servicing Rights [Member]
Net carrying value of intangible assets
Loan servicing rights	51,393		11,122
Other intangible assets:
Total other intangible assets	9,465	$ 9,677	11,122	$ 11,540	$ 12,307	$ 12,217
Core deposit intangible assets [Member]
Other intangible assets:
Total other intangible assets	35,618		26,654
Noncompete Agreements [Member]
Other intangible assets:
Total other intangible assets	$ 82		$ 328