Earning per Share - Additional Information (Detail)	1 Months Ended
May 25, 2011
Computation Of Earnings Per Share Line Items
Stock split	1.5
Record date of stock split	Jun. 10, 2011

This item represents the conversion ratio used in the calculation of a stock split.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Stock Split

-URI http://asc.fasb.org/extlink&oid=6525746

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187143-122770

Name:	us-gaap_StockholdersEquityNoteStockSplitConversionRatio
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration