Summary of Impact of Restatements on Each Affected Line of Consolidated Statements of Cash Flows (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Jun. 30, 2012	Jun. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Changes in operating assets and liabilities, net of effect of acquisitions:
Prepaid expenses and other assets	$ (268)	$ 944	$ (701)	$ 150	$ (1,485)	$ (519)	$ (842)	$ 168	$ (414)
Deferred revenues	370	677	867	1,094	248	1,863	680	8,103	231
Net cash (used in)/provided by operating activities	(4,144)	(2,121)	(2,572)	(2,578)	(5,128)	(2,470)	(6,749)	(6,727)	2,249
As Reported
Changes in operating assets and liabilities, net of effect of acquisitions:
Prepaid expenses and other assets	55	886	(433)	275	(1,247)	(107)	(368)	2,073	(113)
Deferred revenues	47	735	599	969	10	1,451	206	6,198	(70)
Net cash (used in)/provided by operating activities	(4,144)	(2,121)	(2,572)	(2,578)	(5,128)	(2,470)	(6,749)	(6,727)	2,249
Adjustments
Changes in operating assets and liabilities, net of effect of acquisitions:
Prepaid expenses and other assets	(323)	58	(268)	(125)	(238)	(412)	(474)	(1,905)	(301)
Deferred revenues	323	(58)	268	125	238	412	474	1,905	301
Net cash (used in)/provided by operating activities	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0