Summary of Fair value of Total Consideration for IdOnDemand, Fair Value of Net Identifiable Assets Acquired and Goodwill Recorded (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011		Dec. 31, 2010	May 02, 2011 idOnDemand, Inc.
Business Acquisition [Line Items]
Cash consideration					$ 2,396
Fair value of common stock					3,024
Fair value of contingent consideration					4,758
Fair value of total consideration transferred					10,178
Fair value of noncontrolling interest					468
Fair value of controlling and noncontrolling interest					10,646
Fair value of net identifiable assets acquired					(2,847)
Goodwill	$ 48,950	$ 58,404	[1]	$ 47,126	$ 7,799

[1] The condensed consolidated balance sheet has been derived from the audited consolidated financial statements at December 31, 2011 but does not include all the information and footnotes required by U.S. generally accepted accounting principles for complete financial statements.