Summary of Significant Accounting Policies (Details)		12 Months Ended
	Sep. 02, 2016 USD ($)	Dec. 31, 2016 USD ($) vote branch	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 01, 2016 $ / shares
Property, Plant and Equipment [Line Items]
Net impact from FDIC shared-loss termination		$ 16,559,000	$ 0	$ 0
Gain on acquisitions		5,831,000	42,930,000	$ 0
Nonmarketable Securities and Federal Home Loan Bank Stock		$ 43,800,000	37,700,000
Period fair values are subject to refinement		1 year
Number of branches | branch		550
Net deferred fees on non-PCI loans		$ 6,700,000	16,600,000
Baseline for measurement		500,000
Securities Sold under Agreements to Repurchase		620,772,000	622,182,000
Short-term borrowings		603,487,000	594,733,000
Amortization Method Qualified Affordable Housing Project Investments		$ 109,800,000	$ 85,600,000
Class A Common Stock
Property, Plant and Equipment [Line Items]
Votes per share of common stock | vote		1
Class B Common Stock
Property, Plant and Equipment [Line Items]
Votes per share of common stock | vote		16
Premises | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of asset		7 years
Premises | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of asset		40 years
Furniture, Software, and Equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life of asset		3 years
Furniture, Software, and Equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life of asset		10 years
Cordia Bancorp Inc.
Property, Plant and Equipment [Line Items]
Business Acquisition, Share Price | $ / shares					$ 5.15
Total purchase price	$ 37,053,000