Guarantor Financial Information (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed consolidating financial statements
Operating activities	$ 189,222	$ 280,047	$ 208,251
Investing activities	(476,033)	(404,913)	(203,783)
Financing activities	280,012	133,671	(9,761)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(6,799)	8,805	(5,293)
Beginning of period	17,525	8,720	14,013
End of period	10,726	17,525	8,720
Issuer
Condensed consolidating financial statements
Operating activities	92,521	209,886	114,960
Investing activities	(432,433)	(389,681)	(161,742)
Financing activities	333,703	186,994	39,983
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(6,209)	7,199	(6,799)
Beginning of period	12,239	5,040	11,839
End of period	6,030	12,239	5,040
Guarantor Subsidiaries
Condensed consolidating financial statements
Operating activities	89,923	60,319	84,947
Investing activities	(36,822)	(5,390)	(33,697)
Financing activities	(53,691)	(53,323)	(49,744)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(590)	1,606	1,506
Beginning of period	5,286	3,680	2,174
End of period	4,696	5,286	3,680
Adjustments/Eliminations
Condensed consolidating financial statements
Operating activities	6,778	9,842	8,344
Investing activities	(6,778)	(9,842)	(8,344)
Financing activities	0	0	0
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	0	0	0
Beginning of period	0	0	0
End of period	$ 0	$ 0	$ 0