Nature of Operations and Basis of Presentation - Additional Information (Detail)	Mar. 31, 2012 Point Location
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of data centers	42
Number of service centers	83
Networked
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of points of presence	25
Standalone
Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items]
Number of points of presence	1