Summary of Quarterly Results of Operations (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 93,194	[1]	$ 95,332	[1]	$ 86,221	[1]	$ 85,090	[1]	$ 78,622		$ 96,033		$ 92,842		$ 94,794		$ 359,837	$ 362,291	$ 487,384
Gross profit	38,626		35,906		38,235		34,799		31,797		35,783		35,907		35,481		147,566	138,968	160,207
Net income (loss)	$ (348)		$ (1,964)		$ 1,058		$ (477)		$ (55,742)		$ (155)		$ (1,871)		$ (829)		$ (1,731)	$ (58,597)	$ (97,988)
Net loss per share basic	$ (0.01)		$ (0.03)		$ 0.02		$ (0.01)
Net loss per share diluted	$ (0.01)	[2]	$ (0.03)	[2]	$ 0.02	[2]	$ (0.01)	[2]
Net loss per share-basic and diluted									$ (0.95)	[2]	$ 0	[2]	$ (0.03)	[2]	$ (0.01)	[2]	$ (0.03)	$ (1.00)	$ (1.69)

[1] 1 During the year ended December 31, 2014, we recognized a one-time favorable 2014 change in estimate of approximately $4,700 associated with our applications subscriber-based revenue.

[2] Shares issuable via the convertible notes are included if dilutive, in which case tax-effected interest expense on the debt is excluded from the determination of net income (loss) per share - diluted. For all periods reported in 2014 and 2013 the shares issuable via the convertible notes were anti-dilutive and the tax-effected interest expense was excluded in determining net income (loss) per share.