Balance Sheet Offsetting (Details) - Interest Rate Contract - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 25,486	$ 65,596
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	25,486	65,596
Financial instruments	(24,210)	(22,873)
Collateral	(1,044)	(41,879)
Net amount	232	843
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	52,768	22,951
Gross amounts offset in the balance sheet	0	0
Net amounts presented in the balance sheet	52,768	22,951
Financial instruments	(24,210)	(22,873)
Collateral	(25,889)	(63)
Net amount	$ 2,669	$ 16

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