Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 943	$ (10,378)	$ (7,021)	$ (23,988)
Other comprehensive income, net of tax:
Unrealized gain (loss) resulting from changes in fair value of marketable securities	3	6	(31)	3
Other comprehensive income (loss), net of tax	3	6	(31)	3
Comprehensive income (loss)	946	(10,372)	(7,052)	(23,985)
Less: Comprehensive (loss) income attributable to noncontrolling interests	(82)	(3,723)	1,226	(3,910)
Comprehensive income (loss) attributable to common stockholders	$ 1,028	$ (6,649)	$ (8,278)	$ (20,075)