Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Offsetting Liabilities
Gross Amounts Recognized	$ 172,091	$ 172,907
Gross Amounts Offset	0	0
Net Amounts Presented	172,091	172,907
Gross Amounts Not Offset, Financial Instruments	(4,494)	(1,214)
Gross Amounts Not Offset, Cash Collateral	(155,273)	(151,852)
Net Amount	12,324	19,841
Repurchase agreements
Offsetting Repurchase Agreement Liabilities
Gross Amounts Recognized	150,000	150,000
Gross Amounts Offset	0	0
Net Amounts Presented	150,000	150,000
Gross Amounts Not Offset, Financial Instruments	0	0
Gross Amounts Not Offset, Cash Collateral	(150,000)	(150,000)
Net Amount	0	0
Interest rate swaps
Offsetting Assets
Gross Amounts Recognized	78,782	48,642
Gross Amounts Offset	0	0
Net Amounts Presented	78,782	48,642
Gross Amounts Not Offset, Financial Instruments	(4,494)	(1,214)
Gross Amounts Not Offset, Cash Collateral	0	0
Net Amount	74,288	47,428
Offsetting Liabilities
Gross Amounts Recognized	22,091	22,907
Gross Amounts Offset	0	0
Net Amounts Presented	22,091	22,907
Gross Amounts Not Offset, Financial Instruments	(4,494)	(1,214)
Gross Amounts Not Offset, Cash Collateral	(5,273)	(1,852)
Net Amount	$ 12,324	$ 19,841