Net Loss Per Share - Computation of Basic and Diluted Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Numerator (both basic and diluted):
Loss from continuing operations	$ (43,901)	$ (29,153)	$ (39,725)	$ (136,429)	$ (32,522)	$ (24,778)	$ (19,315)	$ (14,786)	$ (249,208)	$ (91,401)
Loss from discontinued operations, net of tax	$ (2,716)	$ (2,926)	$ (4,873)	$ (8,452)	$ (55,245)	$ (14,100)	$ (8,462)	$ (12,690)	(18,967)	(90,497)
Net loss available to common stockholders, basic									(268,175)	(181,898)
Net loss available to common stockholders, diluted									$ (268,175)	$ (181,898)
Denominator:
Weighted average shares used for basic and diluted earnings per share (in shares)	24,900	24,927	24,957	24,914	24,924	25,606	27,204	26,850	24,925	26,141
Loss from continuing operations per share, basic and diluted (in dollars per share)	$ (1.76)	$ (1.17)	$ (1.59)	$ (5.48)	$ (1.30)	$ (0.97)	$ (0.71)	$ (0.55)	$ (10.00)	$ (3.50)
Loss from discounted operations per share, basic and diluted (in dollars per share)	(0.11)	(0.12)	(0.19)	(0.34)	(2.22)	(0.55)	(0.31)	(0.47)	(0.76)	(3.46)
Net loss per share, basic and diluted (in dollars per share)	$ (1.87)	$ (1.29)	$ (1.78)	$ (5.82)	$ (3.52)	$ (1.52)	$ (1.02)	$ (1.02)	$ (10.76)	$ (6.96)