Long-Term Borrowings - Components (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Long-term borrowings
Long-term borrowings	$ 600,026	$ 34
Capital lease
Long-term borrowings
Long-term borrowings	$ 26	$ 34
Interest rate (as a percent)	6.78%	6.78%
FHLB short-term advance
Long-term borrowings
Long-term borrowings	$ 600,000
Remaining borrowing capacity	$ 1,300,000	$ 1,800,000
Interest rate (as a percent)	2.80%