XML 21 R55.htm IDEA: XBRL DOCUMENT v2.4.1.9
Property and Equipment, Net - Property and Equipment - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Property, Plant and Equipment [Abstract]      
Depreciation expense $ 15.3us-gaap_Depreciation $ 15.6us-gaap_Depreciation $ 15.9us-gaap_Depreciation