Repurchase Agreements (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Dec. 31, 2016
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	[1]	$ 244,646	$ 230,612
Certificates of Deposit, at Carrying Value		920	917
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	[1]	244,646	225,605
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	[1]	0	0
30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	[1]	0	5,007
Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase	[1]	0	0
Commercial Borrower
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			5,007
Commercial Borrower | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			5,007
Commercial Borrower | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			3,715
Commercial Borrower | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			3,715
Commercial Borrower | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			1,292
Commercial Borrower | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Commercial Borrower | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			1,292
Commercial Borrower | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase			0
Retail [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		244,646	225,605
Retail [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		244,646	225,605
Retail [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		98,460	117,784
Retail [Member] | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		98,460	117,784
Retail [Member] | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Mortgage-backed securities issued or guaranteed by U.S. government sponsored enterprises [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		145,556	107,821
Retail [Member] | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		145,556	107,821
Retail [Member] | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	0
Retail [Member] | Collateralized mortgage obligations issued or guaranteed by U.S. government sponsored enterprises [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0	$ 0
Retail [Member] | Obligations of states and political subdivisions [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		630
Retail [Member] | Obligations of states and political subdivisions [Member] | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		630
Retail [Member] | Obligations of states and political subdivisions [Member] | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0
Retail [Member] | Obligations of states and political subdivisions [Member] | 30 - 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		0
Retail [Member] | Obligations of states and political subdivisions [Member] | Greater than 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Securities Sold under Agreements to Repurchase		$ 0

[1] (1) Presented within short-term borrowings on the consolidated statements of condition.