CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	[1]	Sep. 30, 2018	Sep. 30, 2017	[1]
Statement of Comprehensive Income [Abstract]
Net income attributable to common stockholders	$ 14,986	$ 8,030		$ 23,404	$ 11,874	[2]
Other comprehensive (loss) income:
Foreign currency translation adjustments	(193)	2,041		(1,811)	6,673
Foreign currency adjustments to net income upon liquidation of investment in foreign entities	0	(175)		30	(204)
Other comprehensive (loss) income	(193)	1,866		(1,781)	6,469
Comprehensive income	$ 14,793	$ 9,896		$ 21,623	$ 18,343

[1] As of January 1, 2018, the Company adopted ASC 606 using the full retrospective method. Accordingly, the Company has recast certain amounts in the prior periods presented. See Note 1 below for additional discussion.

[2] As of January 1, 2018, the Company adopted ASC 606 using the full retrospective method. Accordingly, the Company has recast certain amounts in the prior period presented. Also as of January 1, 2018, the Company adopted Accounting Standards Update No. 2016-18, "Statement of Cash Flows (Subtopic 230): Restricted Cash," and recast the prior period presented. See Note 1 below for additional discussion.