Sale and Leaseback Transactions - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Sale and Leaseback Transactions [Abstract]
Deferred gain on sale of property	$ 42,000,000us-gaap_DeferredGainOnSaleOfProperty	$ 45,000,000us-gaap_DeferredGainOnSaleOfProperty
Deferred gains	$ 39,000,000	$ 41,339,000

The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 840

-SubTopic 40

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=21918046&loc=d3e50609-112754

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