Repurchase Agreements (Details) - Securities Sold under Agreements to Repurchase [Member] - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Carrying value of investment securities available for sale pledged as collateral under repurchase agreements	$ 296,300	$ 288,100
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	261,298	251,225
Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	114,064	105,670
Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	21,000	500
30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	35,000	24,335
Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	91,234	120,720
U.S. Treasury and Government Agencies [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	93,566	78,280
U.S. Treasury and Government Agencies [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	26,760	19,184
U.S. Treasury and Government Agencies [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	8,706	0
U.S. Treasury and Government Agencies [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	18,137	10,401
U.S. Treasury and Government Agencies [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	39,963	48,695
State and Political Subdivisions [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	67,910	69,985
State and Political Subdivisions [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	55,014	58,676
State and Political Subdivisions [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	2,536	494
State and Political Subdivisions [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	1,021	1,656
State and Political Subdivisions [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	9,339	9,159
U.S. Government Sponsored Agency Mortgage-backed Securities [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	99,822	102,960
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Overnight and Continuous [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	32,290	27,810
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Up to 30 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	9,758	6
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | 30-90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	15,842	12,278
U.S. Government Sponsored Agency Mortgage-backed Securities [Member] | Greater Than 90 Days [Member]
Remaining contractual maturity of securities sold under agreements to repurchase by class of collateral pledged [Abstract]
Repurchase agreements and repurchase-to-maturity transactions	$ 41,932	$ 62,866