Derivative Instruments - Offsetting of Derivatives (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Offsetting assets:
Gross Amounts of Recognized Assets	$ 22	$ 1,643
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	22	1,643
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	(1,054)
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Received	0	0
Net Amount	22	589
Offsetting liabilities:
Gross Amounts of Recognized Liabilities	607,992	275,679
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	607,992	275,679
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	(1,054)
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Received	0	0
Net Amount	$ 607,992	$ 274,625