Share-based Compensation - Summary of Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash stock compensation	$ 1,578	$ 6,561	$ 9,581	$ 10,492
Continuing operations
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash stock compensation	1,459	6,388	9,194	9,572
Continuing operations | Stock options, net of estimated forfeitures
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash stock compensation	708	1,932	2,871	(3,333)
Continuing operations | Restricted stock awards
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash stock compensation	751	4,456	6,323	12,905
Discontinued operations
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total non-cash stock compensation	$ 119	$ 173	$ 387	$ 920