Intangible Assets Subject to Amortization (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross Amount	$ 569,755	$ 43,849
Accumulated Amortization	(23,490)	(19,293)
Net Balance	546,265	24,556
Noncompetition agreements
Finite-Lived Intangible Assets [Line Items]
Gross Amount	6,274	6,274
Accumulated Amortization	(5,874)	(5,583)
Net Balance	400	691
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross Amount	36,610	20,660
Accumulated Amortization	(6,824)	(6,160)
Net Balance	29,786	14,500
Operating Permits
Finite-Lived Intangible Assets [Line Items]
Gross Amount	498,685	6,800
Accumulated Amortization	(3,551)	(1,394)
Net Balance	495,134	5,406
Use Rights And Other
Finite-Lived Intangible Assets [Line Items]
Gross Amount	15,386	10,115
Accumulated Amortization	(6,669)	(6,156)
Net Balance	8,717	3,959
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Amount	12,800
Accumulated Amortization	(572)
Net Balance	$ 12,228