Intangible Assets (Detail) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount $ 182,277 $ 186,366
Accumulated Amortization (32,914) (12,490)
Intangible Assets, Net 149,363 173,876
Remaining Useful Life 13 years 4 months 24 days 14 years 2 months 12 days
Customer relationships
   
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 163,106 166,426
Accumulated Amortization (28,127) (8,945)
Intangible Assets, Net 134,979 157,481
Remaining Useful Life 13 years 7 months 6 days 14 years 3 months 18 days
Disposal permits
   
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 1,819 2,588
Accumulated Amortization (682) (472)
Intangible Assets, Net 1,137 2,116
Remaining Useful Life 7 years 2 months 12 days 8 years 2 months 12 days
Customer Contracts
   
Finite-Lived Intangible Assets [Line Items]    
Gross Carrying Amount 17,352 17,352
Accumulated Amortization (4,105) (3,073)
Intangible Assets, Net $ 13,247 $ 14,279
Remaining Useful Life 13 years 14 years