Summary of Significant Accounting Policies - Litigation and Non-routine Costs, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Litigation and non-routine costs, net:
Audit Committee Investigation and related matters	$ 22,767	$ 17,232	$ 37,458	$ 38,960
Legal fees and expenses	0	123	2	135
Litigation settlements	0	90,000	12,235	90,000
Total costs	22,767	107,355	49,695	129,095
Insurance recoveries	0	(268)	(48,420)	(268)
Other recoveries	(26,536)	0	(26,536)	0
Total	$ (3,769)	$ 107,087	$ (25,261)	$ 128,827