Subsequent Events - Additional Information (Detail) (Subsequent Event, Vacant Land in Freetown, Massachusetts, USD $) In Millions, unless otherwise specified	0 Months Ended
Feb. 24, 2015
Subsequent Event \| Vacant Land in Freetown, Massachusetts
Subsequent Event [Line Items]
Land disposals	$ 4

Amount of divestiture of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentDisposals
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration