Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
Dec. 31, 2013 Purchase Option Exercised [Member] Containers	Mar. 31, 2014 Purchase Contract [Member] Vehicle
Commitments and Contingencies Disclosure [Line Items]
Purchase contract units, tractors		300
Total costs of purchasing tractors		$ 39.3
Number of containers to be purchased at lease expiration date	2,000
Total price of containers to be purchased at lease expiration date	$ 7.8
Leases expiry date	2014

Minimum amount of other commitment not otherwise specified in the taxonomy. Excludes commitments explicitly modeled in the taxonomy, including but not limited to, long-term and short-term purchase commitments, recorded and unrecorded purchase obligations, supply commitments, registration payment arrangements, leases, debt, product warranties, guarantees, environmental remediation obligations, and pensions.

No definition available.

Name:	us-gaap_OtherCommitment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant