Adjustments to Unaudited Selected Quarterly Data Previously Reported Resulted from Adoption of New Standards (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended												6 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2016	[1]	Sep. 30, 2016		Jun. 30, 2016		Mar. 31, 2016		Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Unaudited condensed consolidated statements of operations data:
Income before provision for income taxes	$ 10,696		$ 5,515	[1]	$ 5,498	[1]	$ 13,493	[1]	$ 36,498	$ 10,246	$ 4,501	$ 9,260			$ 35,202	$ 60,505	$ 47,994
Provision for income taxes			2,214		962		3,093								8,216	24,183	14,739
Net income	$ 8,749		$ 3,301	[1]	$ 4,536	[1]	$ 10,400	[1]	$ 20,958	$ 6,325	$ 3,104	$ 5,935			$ 26,986	$ 36,322	$ 33,255
Effective tax rate			40.10%		17.50%		22.90%								23.30%	40.00%	30.70%
Earnings per share:
Basic	$ 0.11		$ 0.04	[1]	$ 0.06	[1]	$ 0.14	[1]	$ 0.27	$ 0.08	$ 0.04	$ 0.08			$ 0.35	$ 0.47	$ 0.44
Diluted	$ 0.11		$ 0.04	[1]	$ 0.06	[1]	$ 0.13	[1]	$ 0.26	$ 0.08	$ 0.04	$ 0.08			$ 0.34	$ 0.46	$ 0.42
Weighted-average number of common shares outstanding:
Diluted			79,548		79,422		79,235								79,732	79,043	78,531
Unaudited condensed consolidated statements of cash flows data:
Net cash provided by operating activities							$ 10,040						$ 11,569	$ 20,556	$ 39,874	$ 67,803	$ 103,276
Net cash used in financing activities							(19,822)						(31,666)	(43,031)	$ (51,716)	$ (40,659)	$ (27,419)
As Reported
Unaudited condensed consolidated statements of operations data:
Income before provision for income taxes			$ 5,515		$ 5,498		13,493
Provision for income taxes			3,097		1,851		4,488
Net income			$ 2,418		$ 3,647		$ 9,005
Effective tax rate			56.20%		33.70%		33.30%
Earnings per share:
Basic			$ 0.03		$ 0.05		$ 0.12
Diluted			$ 0.03		$ 0.05		$ 0.11
Weighted-average number of common shares outstanding:
Diluted			79,082		78,969		78,878
Unaudited condensed consolidated statements of cash flows data:
Net cash provided by operating activities							$ 8,642						9,299	17,396
Net cash used in financing activities							$ (18,424)						$ (29,396)	$ (39,871)

[1] The Company elected to early adopt ASU 2016-09 in the fourth quarter of 2016, which requires, among other things, excess tax benefits to be recorded as a reduction of the provision for income taxes in the consolidated statement of operations, whereas they were previously recognized in equity. The Company is required to reflect any adoption adjustments as of January 1, 2016, the beginning of the annual period that includes the period of adoption. As such, certain information above includes the impact of the ASU 2016-09 adoption. See Note 2 "Significant Accounting Policies-New accounting pronouncements" for additional information related to this adoption.