Loans - Schedule of Loans Renegotiated in Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Loans and Leases Receivable, Troubled Debt Restructuring [Line Items]
Loans renegotiated in troubled debt restructurings	$ 29,400,000		$ 29,400,000		$ 44,500,000
Loans renegotiated in troubled debt restructurings, non-accrual loans	22,200,000		22,200,000		31,900,000
Loans renegotiated in troubled debt restructurings, accrual loans	7,200,000		7,200,000		$ 12,600,000
Loans restructured during period			0
Charge-offs directly related to modifying troubled debt restructurings	0	$ 0	0	$ 0
Balance of defaulted loans under trouble debt restructurings			0
Commitments to lend additional funds	$ 0		$ 0