CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]
Beginning Balance at Dec. 31, 2010	$ 361,228	$ 401	$ 219,240	$ 137,629	$ (65,543)	$ 69,501
Beginning Balance, Shares at Dec. 31, 2010		40,103
Issuance of common shares:
Exercise of stock options	924	2	922	0	0	0
Exercise of stock options, shares		167
Restricted stock awards	2,030	2	2,028	0	0	0
Restricted stock awards, Shares		273
Employee stock-based compensation	2,611	0	2,611	0	0	0
Conversion of 8.25% senior convertible notes	465	1	464	0	0	0
Conversion of 8.25% senior convertible notes, Shares		82
Purchase of treasury shares	(561)	0	0	0	(561)	0
Tax benefits related to equity compensation	2,535	0	2,535	0	0	0
Dividend to noncontrolling interest owner	0
Net income	70,137	0	0	55,960	0	14,177
Ending Balance at Dec. 31, 2011	439,369	406	227,800	193,589	(66,104)	83,678
Ending Balance, Shares at Dec. 31, 2011		40,625
Issuance of common shares:
Exercise of stock options	719	1	718	0	0	0
Exercise of stock options, shares		122
Restricted stock awards	1,566	2	1,564	0	0	0
Restricted stock awards, Shares		203
Employee stock-based compensation	1,934	0	1,934	0	0	0
Conversion of 8.25% senior convertible notes	29,107	49	29,058	0	0	0
Conversion of 8.25% senior convertible notes, Shares		4,932
Warrants issued	2,572	0	2,572	0	0	0
Purchase of treasury shares	(41)	0	0	0	(41)	0
Dividend to noncontrolling interest owner	0
Net income	1,212	0	0	(12,211)	0	13,423
Ending Balance at Dec. 31, 2012	476,438	458	263,646	181,378	(66,145)	97,101
Ending Balance, Shares at Dec. 31, 2012		45,882
Issuance of common shares:
Exercise of stock options	122	0	122	0	0	0
Exercise of stock options, shares		20
Sales of common shares	9,298	25	9,273	0	0	0
Sales of common shares, Shares		2,495
Restricted stock awards	928	4	924	0	0
Restricted stock awards, Shares		269
Employee stock-based compensation	2,118	0	2,118	0	0	0
Purchase of treasury shares	(77)	0	0	0	(77)	0
Increase in equity held by noncontrolling interests due to sale of interest in affiliate	144,796					144,796
Dividend to noncontrolling interest owner	(10,370)	0	0	0	0	(10,370)
Net income	(77,456)	0	0	(89,096)	0	11,640
Ending Balance at Dec. 31, 2013	$ 545,797	$ 487	$ 276,083	$ 92,282	$ (66,222)	$ 243,167
Ending Balance, Shares at Dec. 31, 2013		48,666