Selected Quarterly Information (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
Selected Quarterly Financial Information [Line Items]
Revenue	$ 168,924		$ 137,631		$ 142,985		$ 140,464		$ 153,382	[1]	$ 122,011		$ 117,315		$ 116,246		$ 590,004		$ 508,954		$ 461,710
Gross profit	122,816		91,249		96,294		94,551		109,605	[1]	83,913		79,437		78,593		404,910		351,548		304,330
Income from operations	29,693		4,997		2,222		14,627		24,304	[1]	13,789		7,053		12,951		51,539		58,097		31,426
Income before provision for income taxes	28,714		2,352		2,387		14,541		24,308	[1]	13,410		6,657		12,018		47,994		56,393		30,945
Net income	$ 20,104		$ 1,882		$ 1,504		$ 9,765		$ 15,561	[1]	$ 8,710		$ 4,703		$ 9,069		$ 33,255		$ 38,043		$ 21,868
Net earnings per share, basic	$ 0.27	[2]	$ 0.02	[2]	$ 0.02	[2]	$ 0.13	[2]	$ 0.21	[1],[2]	$ 0.11	[2]	$ 0.06	[2]	$ 0.12	[2]	$ 0.44	[3],[4]	$ 0.50	[3],[4]	$ 0.29	[3],[4]
Net earnings per share, diluted	$ 0.26	[2]	$ 0.02	[2]	$ 0.02	[2]	$ 0.12	[2]	$ 0.20	[1],[2]	$ 0.11	[2]	$ 0.06	[2]	$ 0.12	[2]	$ 0.42	[3],[4]	$ 0.49	[3],[4]	$ 0.28	[3],[4]

[1] Reflects the Company's acquisition of Antenna on October 9, 2013. See Note 8 "Acquisitions" for pro forma information for the year ended December 31, 2013.

[2] On March 6, 2014, the Company's Board of Directors approved a two-for-one stock split of the Company's common stock, effected in the form of a common stock dividend. See Note 1 "Basis of Presentation" (d) for further discussion of the Stock Split.

[3] The number of common shares and per share amounts have been retroactively restated for all prior periods presented to reflect the Company's two-for-one common stock split effected in the form of a common stock dividend distributed on April 1, 2014.

[4] The number of common shares and per share amounts have been retroactively restated for all prior periods presented to reflect the Company's two-for-one common stock split effected in the form of a common stock dividend distributed on April 1, 2014. See Note 1 "Basis of Presentation" (d) for further discussion of the Stock Split.