Goodwill and Other Intangible Assets (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segment	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 469,433,000	$ 469,433,000	$ 469,433,000	$ 469,433,000	$ 469,433,000
Number of operating segments | segment			3
Goodwill impairment					$ 0
Finite-Lived Intangible Assets [Line Items]
Amortization expense	1,762,000	2,050,000	$ 3,579,000	4,154,000
Core Deposit Intangibles
Finite-Lived Intangible Assets [Line Items]
Impairment write-downs			0	0
Amortization expense	$ 1,800,000	$ 2,100,000	$ 3,600,000	$ 4,200,000