Stockholders' Equity - Additional Information (Detail) (USD $) In Billions, unless otherwise specified	1 Months Ended	6 Months Ended
Sep. 16, 2013	Dec. 31, 2013
Share Repurchases [Line Items]
Amount available for repurchase under the current share repurchase program approved by the company's Board of Directors	$ 40.0
Unused amount of share repurchase program		$ 38.0

Amount remaining of a stock repurchase plan authorized by an entity's Board of Directors.

No definition available.

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