Subsequent Events - Additional Information (Detail) (Subsequent Event, USD $) In Millions, unless otherwise specified	1 Months Ended
Apr. 30, 2013
Subsequent Event
Subsequent Event [Line Items]
Total proceeds from sale of business	$ 18.5
Gain on sale of business	$ 2

Aggregate cash proceeds received from a combination of transactions in which noncurrent assets are sold, which may include the sale of a business, an investment in an affiliate (including an equity method investee), property, plant and equipment and intangible assets. Excludes sales of trading, available-for-sale, and held-to-maturity securities.

No definition available.

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