CONDENSED CONSOLIDATED STATEMENTS OF EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Treasury stock, at cost	Non-controlling interests
Balance at Dec. 31, 2013	$ 157,741	$ 25,413	$ 89,273	$ 239,561	$ (197,548)	$ 1,042
Balance (in shares) at Dec. 31, 2013		25,413
Increase (Decrease) in Equity
Net income	94,878			93,732		1,146
Distributions to non-controlling interest holders	(1,207)					(1,207)
Share-based compensation expense	1,130		1,130
Exercise of stock options	639			(2,932)	3,571
Repurchase of shares	(80,702)				(80,702)
Balance at Jun. 30, 2014	172,479	$ 25,413	90,403	330,361	(274,679)	981
Balance (in shares) at Jun. 30, 2014		25,413
Balance at Dec. 31, 2014	41,443	$ 25,413	91,509	367,967	(444,495)	1,049
Balance (in shares) at Dec. 31, 2014		25,413
Increase (Decrease) in Equity
Net income	51,254			49,648		1,606
Distributions to non-controlling interest holders	(1,347)					(1,347)
Share-based compensation expense	1,315		1,315
Exercise of stock options	203			(1,701)	1,904
Repurchase of shares	(43,965)				(43,965)
Balance at Jun. 30, 2015	$ 48,903	$ 25,413	$ 92,824	$ 415,914	$ (486,556)	$ 1,308
Balance (in shares) at Jun. 30, 2015		25,413