Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 20,523	$ 16,276	$ 34,296	$ 36,846
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustment, net of tax of ($348) for the nine months ended September 30, 2016.	10	0	12	569
Unrealized gain on available-for-sale securities, net of tax of ($32) and $31 for the three months ended September 30, 2017 and 2016, respectively and ($115) and ($140) for the nine months ended September 30, 2017 and 2016, respectively.	38	(50)	172	230
Other comprehensive income (loss)	48	(50)	184	799
Comprehensive income (loss)	20,571	16,226	34,480	37,645
Comprehensive (income) loss attributable to noncontrolling interests	(1,731)	(651)	(2,782)	(770)
Comprehensive Income (Loss) Attributable to Stockholders	$ 18,840	$ 15,575	$ 31,698	$ 36,875