LHFI and Allowance for Loan Losses, LHFI - Additional Information (Details 1)	12 Months Ended
	Dec. 31, 2016 USD ($) Region	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Financing Receivable Impaired [Line Items]
Maximum concentration of loan as a percentage of total LHFI	10.00%
Key market regions | Region	5
Loans and Leases Receivable, Related Parties	$ 47,100,000	$ 82,200,000
New loan advances to related party	390,900,000
Loan repayment by related party	389,600,000
Loan increase decreases from changes in executive officers and directors	36,400,000
Carrying amounts of nonaccrual LHFI considered for impairment analysis	49,200,000	55,300,000
Nonaccrual	49,234,000	55,312,000
Minimum loan amount for loan to be individually assessed for impairment	500,000
Nonaccrual financing receivable, specifically evaluated for impairment	23,700,000	26,500,000
Nonaccrual financing receivable, allowance for credit losses, charge-offs, specifically evaluated for impairment	6,400,000	10,100,000	$ 137,000
Nonaccrual financing receivable, allowance for credit losses, deterioration value reserve	3,000,000	7,000,000
Nonaccrual financing receivable specifically evaluated for impairment allowance for credit losses provisions	(2,200,000)	4,800,000	3,500,000
Nonaccrual financing receivable, not specifically evaluated for impairment	25,500,000	28,800,000
Nonaccrual financing receivable, allowance for credit losses, not specifically evaluated for impairment	2,500,000	2,000,000
Amount held by company of foreclosure or in substance repossession of consumer mortgage LHFI classified as TDRs	269,000	1,000,000
TDRs Classified as Consumer mortgage LHFI in the process of formal disclosure	101,000	83,000
LHFI Classified as TDRs	14,500,000	9,700,000	11,300,000
LHFI classified as TDRs from credits with interest only payments	9,800,000	5,900,000	7,400,000
Financing receivable, related allowance	2,200,000	1,800,000	1,700,000
Financing receivable, related charge-offs	1,000,000	806,000	75,000
Troubled Debt Restructurings [Member]
Financing Receivable Impaired [Line Items]
Nonaccrual	$ 14,427,000	$ 7,418,000	$ 9,910,000