Guarantor Financial Information (Details 4) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Condensed consolidating financial statements
Operating activities	$ 10,727	$ 52,159	$ 258,121
Investing activities	313,227	(117,395)	(318,997)
Financing activities	241,291	45,000	62,269
Net increase (decrease) in cash and cash equivalents	565,245	(20,236)	1,393
Beginning of period	7,780	28,016	26,623
End of period	573,025	7,780	28,016
Issuer
Condensed consolidating financial statements
Operating activities	33,099	61,138	178,769
Investing activities	320,038	(113,543)	(274,629)
Financing activities	212,329	35,851	97,384
Net increase (decrease) in cash and cash equivalents	565,466	(16,554)	1,524
Beginning of period	4,663	21,217	19,693
End of period	570,129	4,663	21,217
Guarantor Subsidiaries
Condensed consolidating financial statements
Operating activities	(22,247)	836	69,543
Investing activities	(6,801)	(15,143)	(34,749)
Financing activities	28,961	9,469	(34,987)
Net increase (decrease) in cash and cash equivalents	(87)	(4,838)	(193)
Beginning of period	1,855	6,693	6,886
End of period	1,768	1,855	6,693
Non-Guarantor Subsidiary
Condensed consolidating financial statements
Operating activities	(125)	(10,381)	5,842
Investing activities	(10)	11,857	(5,652)
Financing activities	1	(320)	(128)
Net increase (decrease) in cash and cash equivalents	(134)	1,156	62
Beginning of period	1,262	106	44
End of period	1,128	1,262	106
Adjustments/Eliminations
Condensed consolidating financial statements
Operating activities	0	566	3,967
Investing activities	0	(566)	(3,967)
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