LHFI and Allowance for Loan Losses, LHFI - Additional Information (Details 1)	3 Months Ended
	Mar. 31, 2016 USD ($) Region	Mar. 31, 2015 USD ($)	Dec. 31, 2015 USD ($)
Financing Receivable Impaired [Line Items]
Maximum concentration of loan as a percentage of total LHFI	10.00%
Key market regions | Region	5
Carrying amounts of nonaccrual LHFI considered for impairment analysis	$ 70,700,000		$ 55,300,000
Minimum loan amount for loan to be individually assessed for impairment	500,000
Nonaccrual	70,694,000		55,312,000
Nonaccrual financing receivable, specifically evaluated for impairment	41,100,000		26,500,000
Nonaccrual financing receivable, allowance for credit losses, charge-offs, specifically evaluated for impairment	712,000	$ 234,000
Nonaccrual financing receivable specifically evaluated for impairment allowance for credit losses provisions	551,000	825,000
Nonaccrual financing receivable, allowance for credit losses, deterioration value reserve	9,500,000		7,000,000
Nonaccrual financing receivable, not specifically evaluated for impairment	29,600,000		28,800,000
Nonaccrual financing receivable, allowance for credit losses, not specifically evaluated for impairment	1,900,000		2,000,000
Amount held by company of foreclosure or in substance repossession of consumer mortgage LHFI classified as TDRs	921,000		1,000,000
TDRs Classified as Consumer mortgage LHFI in the process of formal disclosure	61,000		83,000
LHFI Classified as TDRs	9,200,000	10,800,000
LHFI classified as TDRs from credits with interest only payments	5,700,000	6,900,000
Financing receivable, related allowance	1,700,000	1,800,000
Financing receivable, related charge-offs	0	0
Troubled Debt Restructurings [Member]
Financing Receivable Impaired [Line Items]
Nonaccrual	$ 6,945,000	$ 8,472,000	$ 7,400,000