Balance Sheet Offsetting (Details 1) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	$ 300,000	$ 416,640
Gross amount of recognized liabilities for repurchase agreements in offsetting disclosure	300,000	400,000
Amounts related to agreements not included in offsetting disclosure		16,640
Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements		16,640
Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	50,000	25,000
30 to 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	100,000	275,000
91 to 110 days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	150,000	100,000
U.S. Treasuries
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	100,000	100,000
U.S. Treasuries | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements
U.S. Treasuries | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements
U.S. Treasuries | 30 to 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	50,000	100,000
U.S. Treasuries | 91 to 110 days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	50,000
U.S. Government agencies
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements		32
U.S. Government agencies | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements		32
U.S. Government agencies | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements
U.S. Government agencies | 30 to 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements
U.S. Government agencies | 91 to 110 days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements
Mortgage-backed securities
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	200,000	316,608
Mortgage-backed securities | Overnight and Continuous
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements		16,608
Mortgage-backed securities | Up to 30 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	50,000	25,000
Mortgage-backed securities | 30 to 90 Days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	50,000	175,000
Mortgage-backed securities | 91 to 110 days
Assets Sold under Agreements to Repurchase [Line Items]
Remaining Contractual Maturity of the Agreements	$ 100,000	$ 100,000