Investment in Affiliates and Other Assets - Additional Information (Detail) (Collateral Trust, Waste Control Specialists, USD $) In Millions, unless otherwise specified	1 Months Ended
Apr. 30, 2014
Collateral Trust \| Waste Control Specialists
Disclosure - Investment in Affiliates and Other Assets - Additional Information (Detail) [Line Items]
Decrease in restricted cash	$ 18.0

Amount of cash inflow associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities.

No definition available.

Name:	us-gaap_DecreaseInRestrictedCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration