Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Consolidated net income (loss)	$ 87,174	$ 97,431
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	987	3,658
Available for sale securities		999
Total other comprehensive income (loss), net of tax	987	4,657
Comprehensive income (loss)	88,161	102,088
Comprehensive income (loss) from continuing operations attributable to noncontrolling interest in subsidiaries, net of tax	25,381	29,306
Comprehensive income (loss) from discontinued operations attributable to noncontrolling interest in subsidiaries, net of tax		9,983
Less: Total comprehensive income (loss) attributable to noncontrolling interest in subsidiaries, net of tax	25,381	39,289
Comprehensive income (loss) attributable to common stockholders	$ 62,780	$ 62,799