Basis of Presentation - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	Oct. 22, 2014	May 23, 2006
Limits On Use Of Authorized Capital Stock [Line Items]
Limits on use of authorized common stock shares		40
Limits on use of authorized preferred stock shares		2
Common stock, dividends per share declared, subsequent event	$ 0.25

Aggregate dividends declared for each share of common stock outstanding on date subsequent to period end date.

No definition available.

Name:	expo_CommonStockDividendsPerShareDeclaredSubsequentEvent
Namespace Prefix:	expo_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant