Shareholders' Equity - Additional Information (Detail) (Subsequent Event [Member]) In Millions, unless otherwise specified	Feb. 18, 2015
Subsequent Event [Member]
Class Of Stock [Line Items]
Number of shares authorized to be repurchased	1.4

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

No definition available.

Name:	us-gaap_StockRepurchaseProgramNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant