Intangible Assets (Amortization Expense of Core Deposit Intangible Assets) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Carrying amount, accumulated amortization and amortization expense of core deposit intangible assets
Total intangible assets	$ 35,700	$ 26,982
Core deposit intangible assets [Member]
Carrying amount, accumulated amortization and amortization expense of core deposit intangible assets
Gross original amount	52,454	40,055
Accumulated amortization	16,836	13,401
Total intangible assets	$ 35,618	$ 26,654