CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury stock, at cost	Non-controlling interests
Balance at Dec. 31, 2015	$ 52,270	$ 25,413	$ 96,321	$ 369,270	$ 0	$ (440,026)	$ 1,292
Balance (in shares) at Dec. 31, 2015		25,413
Increase (Decrease) in Equity
Net income	51,050			49,077			1,973
Other comprehensive income (loss), net of tax	(2,156)				(2,156)
Distributions to non-controlling interest holders	(1,637)						(1,637)
Share-based compensation expense	4,692		4,692
Exercise of stock options and issuance of restricted shares	8,876			(58,912)		67,788
Repurchase of shares	(34,321)					(34,321)
Balance at Sep. 30, 2016	78,774	$ 25,413	101,013	359,435	(2,156)	(406,559)	1,628
Balance (in shares) at Sep. 30, 2016		25,413
Balance at Dec. 31, 2016	62,194	$ 25,413	107,288	333,786	(1,745)	(403,953)	1,405
Balance (in shares) at Dec. 31, 2016		25,413
Increase (Decrease) in Equity
Net income	24,648			22,541			2,107
Other comprehensive income (loss), net of tax	212				212
Distributions to non-controlling interest holders	(2,143)						(2,143)
Share-based compensation expense	3,237		3,237
Exercise of stock options and issuance of restricted shares	2,084			(11,787)		13,871
Treasury shares withheld for the payment of tax on restricted share issuances	(1,088)			(1,497)		409
Repurchase of shares	(24,995)					(24,995)
Balance at Sep. 30, 2017	$ 64,149	$ 25,413	$ 111,457	$ 342,111	$ (1,533)	$ (414,668)	$ 1,369
Balance (in shares) at Sep. 30, 2017		25,413