Summary of Significant Accounting Policies - Litigation and Other Non-Routine Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Litigation and other non-routine costs:
Audit Committee Investigation and related matters	$ 14,354	$ 3,450	$ 27,025	$ 8,192
Legal fees and expenses	57	13	261	96
Total costs incurred	14,411	3,463	27,286	8,288
Insurance recoveries	0	(546)	0	(10,546)
Total	$ 14,411	$ 2,917	$ 27,286	$ (2,258)