Condensed Consolidating Financial Information - Statements of Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Net Cash Provided by (Used in) Operating Activities	$ 86,116	$ 71,167
Cash flows from investing activities:
Capital expenditures, net of related payables	(31,301)	(23,709)
Proceeds from asset sales	0	4,964
Distributions in excess of earnings from joint ventures	0	249
Distributions from subsidiaries	0	0
Proceeds from repayment of advances to subsidiaries, net	0	0
Loans to parent, net	0	0
Native American development costs	(386)	(760)
Investment in subsidiaries	0	0
Other, net	(746)	(570)
Net cash (used in) provided by investing activities	(32,433)	(19,826)
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	10,000	20,000
Payments under credit agreements with original maturities greater than three months	(48,142)	(65,880)
Distributions to members and noncontrolling interests	(2,485)	(18,877)
Payments on derivative instruments with other-than-insignificant financing elements	(1,786)	(2,441)
Loans from subsidiaries, net	0	0
Payments on advances from parent, net	0	0
Capital contributions from parent	0	0
Payment of note payable	(6,000)	0
Other, net	(2,118)	(997)
Net cash used in financing activities	(50,531)	(68,195)
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	3,152	(16,854)
Balance, beginning of period	115,346	122,702
Balance, end of period	118,498	105,848
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	38,212	39,589
Capital expenditures incurred but not yet paid	18,213	12,472
Parent [Member]
Net Cash Provided by (Used in) Operating Activities	(36,330)	(34,505)
Cash flows from investing activities:
Capital expenditures, net of related payables	(1,706)	(5,540)
Proceeds from asset sales		13
Distributions in excess of earnings from joint ventures		0
Distributions from subsidiaries	7,308	7,052
Proceeds from repayment of advances to subsidiaries, net	31,556	44,697
Loans to parent, net	0	0
Native American development costs	0	0
Investment in subsidiaries	(478)	(29)
Other, net	15	10
Net cash (used in) provided by investing activities	36,695	46,203
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	10,000	20,000
Payments under credit agreements with original maturities greater than three months	(48,142)	(65,090)
Distributions to members and noncontrolling interests	(364)	(17,077)
Payments on derivative instruments with other-than-insignificant financing elements	(1,786)	(1,989)
Loans from subsidiaries, net	53,692	47,909
Payments on advances from parent, net	0	0
Capital contributions from parent	0	0
Payment of note payable	0
Other, net	(1,815)	(500)
Net cash used in financing activities	11,585	(16,747)
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	11,950	(5,049)
Balance, beginning of period	5,897	13,554
Balance, end of period	17,847	8,505
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	37,200	38,230
Capital expenditures incurred but not yet paid	4,777	5,149
Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities	117,461	101,454
Cash flows from investing activities:
Capital expenditures, net of related payables	(29,407)	(17,857)
Proceeds from asset sales		4,255
Distributions in excess of earnings from joint ventures		249
Distributions from subsidiaries	2,120	1,800
Proceeds from repayment of advances to subsidiaries, net	0	0
Loans to parent, net	(53,692)	(47,909)
Native American development costs	(386)	(760)
Investment in subsidiaries	0	0
Other, net	(274)	(551)
Net cash (used in) provided by investing activities	(81,639)	(60,773)
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	0	0
Payments under credit agreements with original maturities greater than three months	0	0
Distributions to members and noncontrolling interests	(7,308)	(7,052)
Payments on derivative instruments with other-than-insignificant financing elements	0	(452)
Loans from subsidiaries, net	0	0
Payments on advances from parent, net	(31,556)	(44,697)
Capital contributions from parent	0	0
Payment of note payable	(6,000)
Other, net	(303)	(497)
Net cash used in financing activities	(45,167)	(52,698)
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	(9,345)	(12,017)
Balance, beginning of period	105,837	104,575
Balance, end of period	96,492	92,558
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	31	486
Capital expenditures incurred but not yet paid	13,369	7,253
Parent and Guarantor Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities	0	0
Cash flows from investing activities:
Capital expenditures, net of related payables	0	0
Proceeds from asset sales		0
Distributions in excess of earnings from joint ventures		0
Distributions from subsidiaries	(7,308)	(7,052)
Proceeds from repayment of advances to subsidiaries, net	(31,556)	(44,697)
Loans to parent, net	53,692	47,909
Native American development costs	0	0
Investment in subsidiaries	0	0
Other, net	0	0
Net cash (used in) provided by investing activities	14,828	(3,840)
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	0	0
Payments under credit agreements with original maturities greater than three months	0	0
Distributions to members and noncontrolling interests	7,308	7,052
Payments on derivative instruments with other-than-insignificant financing elements	0	0
Loans from subsidiaries, net	(53,692)	(47,909)
Payments on advances from parent, net	31,556	44,697
Capital contributions from parent	0	0
Payment of note payable	0
Other, net	0	0
Net cash used in financing activities	(14,828)	3,840
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	0	0
Balance, beginning of period	0	0
Balance, end of period	0	0
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	0	0
Capital expenditures incurred but not yet paid	0	0
Parent and Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities	81,131	66,949
Cash flows from investing activities:
Capital expenditures, net of related payables	(31,113)	(23,397)
Proceeds from asset sales		4,268
Distributions in excess of earnings from joint ventures		249
Distributions from subsidiaries	2,120	1,800
Proceeds from repayment of advances to subsidiaries, net	0	0
Loans to parent, net	0	0
Native American development costs	(386)	(760)
Investment in subsidiaries	(478)	(29)
Other, net	(259)	(541)
Net cash (used in) provided by investing activities	(30,116)	(18,410)
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	10,000	20,000
Payments under credit agreements with original maturities greater than three months	(48,142)	(65,090)
Distributions to members and noncontrolling interests	(364)	(17,077)
Payments on derivative instruments with other-than-insignificant financing elements	(1,786)	(2,441)
Loans from subsidiaries, net	0	0
Payments on advances from parent, net	0	0
Capital contributions from parent	0	0
Payment of note payable	(6,000)
Other, net	(2,118)	(997)
Net cash used in financing activities	(48,410)	(65,605)
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	2,605	(17,066)
Balance, beginning of period	111,734	118,129
Balance, end of period	114,339	101,063
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	37,231	38,716
Capital expenditures incurred but not yet paid	18,146	12,402
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by (Used in) Operating Activities	4,985	4,218
Cash flows from investing activities:
Capital expenditures, net of related payables	(188)	(312)
Proceeds from asset sales		696
Distributions in excess of earnings from joint ventures		0
Distributions from subsidiaries	0	0
Proceeds from repayment of advances to subsidiaries, net	0	0
Loans to parent, net	0	0
Native American development costs	0	0
Investment in subsidiaries	0	0
Other, net	(487)	(29)
Net cash (used in) provided by investing activities	(675)	355
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	0	0
Payments under credit agreements with original maturities greater than three months	0	(790)
Distributions to members and noncontrolling interests	(4,241)	(3,600)
Payments on derivative instruments with other-than-insignificant financing elements	0	0
Loans from subsidiaries, net	0	0
Payments on advances from parent, net	0	0
Capital contributions from parent	478	29
Payment of note payable	0
Other, net	0	0
Net cash used in financing activities	(3,763)	(4,361)
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	547	212
Balance, beginning of period	3,612	4,573
Balance, end of period	4,159	4,785
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	981	873
Capital expenditures incurred but not yet paid	67	70
Eliminations [Member]
Net Cash Provided by (Used in) Operating Activities	0	0
Cash flows from investing activities:
Capital expenditures, net of related payables	0	0
Proceeds from asset sales		0
Distributions in excess of earnings from joint ventures		0
Distributions from subsidiaries	(2,120)	(1,800)
Proceeds from repayment of advances to subsidiaries, net	0	0
Loans to parent, net	0	0
Native American development costs	0	0
Investment in subsidiaries	478	29
Other, net	0	0
Net cash (used in) provided by investing activities	(1,642)	(1,771)
Cash flows from financing activities:
Borrowings under credit agreements with original maturities of three months or less, net	0	0
Payments under credit agreements with original maturities greater than three months	0	0
Distributions to members and noncontrolling interests	2,120	1,800
Payments on derivative instruments with other-than-insignificant financing elements	0	0
Loans from subsidiaries, net	0	0
Payments on advances from parent, net	0	0
Capital contributions from parent	(478)	(29)
Payment of note payable	0
Other, net	0	0
Net cash used in financing activities	1,642	1,771
Cash and cash equivalents:
Increase (decrease) in cash and cash equivalents	0	0
Balance, beginning of period	0	0
Balance, end of period	0	0
Supplemental cash flow disclosures:
Cash paid for interest, net of amounts capitalized	0	0
Capital expenditures incurred but not yet paid	$ 0	$ 0