Securities Sold Under Agreements to Repurchase (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets Sold under Agreements to Repurchase [Line Items]
Carrying amount of securities pledged as collateral	$ 533,399	$ 526,643
Available-for-sale Securities [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Assets Sold under Agreements to Repurchase, Sweep, Interest rate	0.11%
Assets Sold under Agreements to Repurchase, Sweep, Carrying Amount	$ 74,700
Assets Sold under Agreements to Repurchase, Term, Carrying Amounts	$ 25,000
Assets Sold under Agreements to Repurchase, Term, Interest Rate	1.88%
Repurchase Agreements, Sweep [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Carrying amount of securities pledged as collateral	$ 86,000
Repurchase Agreements,Term [Member]
Assets Sold under Agreements to Repurchase [Line Items]
Carrying amount of securities pledged as collateral	$ 28,200