Stock Repurchase Program - Additional Information (Detail) shares in Thousands	Mar. 31, 2018 shares
Class of Stock Disclosures [Abstract]
Stock repurchase program, repurchase authorization	5,000
Stock repurchase program, remaining number of shares authorized to be repurchased	4,750

The remaining 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_StockRepurchaseProgramRemainingNumberOfSharesAuthorizedToBeRepurchased
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant