CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Noncontrolling Interest	Total
Balance at Dec. 31, 2019	$ 1,013	$ 1,258,859	$ 27	$ (946,404)	$ 28,621	$ 342,116
Balance (in shares) at Dec. 31, 2019	101,288
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interest	$ 0	0	0	0	(15,810)	(15,810)
Exercise of stock options, and issuance of common stock units and stock awards, net of repurchase of shares to satisfy tax withholding	$ 0	170	0	0	0	170
Exercise of stock options, and issuance of common stock units and stock awards, net of repurchase of shares to satisfy tax withholding (in shares)	32
Stock-based compensation	$ 0	435	0	0	0	435
Net income	0	0	0	65,437	13,515	78,952
Other comprehensive income	0	0	6	0	0	6
Balance at Mar. 31, 2020	$ 1,013	1,259,464	33	(880,967)	26,326	405,869
Balance (in shares) at Mar. 31, 2020	101,320
Balance at Dec. 31, 2020	$ 1,014	1,260,900	0	(722,002)	67,925	$ 607,837	[1]
Balance (in shares) at Dec. 31, 2020	101,392					101,392
Increase (Decrease) in Stockholders' Equity
Distributions to noncontrolling interest	$ 0	0	0	0	(21,285)	$ (21,285)
Equity activity of noncontrolling interest from a consolidated variable interest entity	0	0	0	0	8	8
Exercise of stock options, and issuance of common stock units and stock awards, net of repurchase of shares to satisfy tax withholding	$ 0	(25)	0	0	0	(25)
Exercise of stock options, and issuance of common stock units and stock awards, net of repurchase of shares to satisfy tax withholding (in shares)	16
Stock-based compensation	$ 0	451	0	0	0	451
Net income	0	0	0	94,123	15,572	109,695
Balance at Mar. 31, 2021	$ 1,014	$ 1,261,326	$ 0	$ (627,879)	$ 62,220	$ 696,681
Balance (in shares) at Mar. 31, 2021	101,408					101,408

[1] Consolidated balance sheet as of December 31, 2020 has been derived from audited consolidated financial statements.