Gross Carrying Amount and Accumulated Amortization by Major Intangible Asset Class (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 764,383	$ 758,212
Accumulated amortization	(71,851)	(60,710)
Total Intangible Assets Subject to Amortization, net	692,532	697,502
Intangible Assets with Indefinite Lives	0	0
Total Intangible Assets, net	692,532	697,502
Aggregate Amortization Expense for the Year	11,869	14,032
Contractual Rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	640,450	640,450
Accumulated amortization	(42,470)	(35,748)
Noncompete Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,450	1,430
Accumulated amortization	(985)	(841)
Lease Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	16,677	16,677
Accumulated amortization	(2,584)	(2,031)
Permitting Permitting Compliance And Zoning Rights
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	82,596	76,956
Accumulated amortization	(14,625)	(12,880)
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	14,493	14,493
Accumulated amortization	(5,927)	(4,466)
Tradenames and Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	5,006	5,006
Accumulated amortization	(2,044)	(1,544)
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,711	3,200
Accumulated amortization	$ (3,216)	$ (3,200)