Business Segment and Entity wide Disclosures - Geographic (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment information:
Total revenues	$ 598,302	$ 1,222,409	$ 1,721,005
United States
Segment information:
Total revenues	562,390	1,157,760	1,630,569
International
Segment information:
Total revenues	$ 35,912	$ 64,649	$ 90,436