XML 87 R41.htm IDEA: XBRL DOCUMENT v2.4.0.6
PROPERTY AND EQUIPMENT - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Property, Plant and Equipment [Line Items]      
Depreciation expense $ 37.1 $ 30.9 $ 28.9