Long-Term Debt - Components (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Long-term debt
Long-term debt	$ 200,034	$ 34
Remaining borrowing capacity	1,400,000
Capital lease
Long-term debt
Long-term debt	$ 34	$ 34
Interest rate (as a percent)	6.78%
FHLB advance
Long-term debt
Long-term debt	$ 200,000
Interest rate (as a percent)	2.79%