Income Tax - Additional Information (Detail) $ in Thousands					3 Months Ended	12 Months Ended
	Jun. 27, 2017 USD ($)	Dec. 01, 2013	Oct. 19, 2012 USD ($)	Oct. 11, 2011	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($) employee	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Income Tax Examination [Line Items]
Unremitted earnings for foreign subsidiaries						$ 35,300
Foreign earnings repatriated	$ 8,900
Foreign income tax rate on distribution	15.00%
Foreign income tax on distribution	$ 1,300
Preferential tax rate		4.00%		7.00%		4.00%
Commitments to maintain tax exemption grant, minimum number of employees to be maintained, first period | employee						750
Commitments to maintain tax exemption grant, minimum number of employees to be maintained, second period | employee						700
Commitments to maintain tax exemption grant, investments			$ 200,000
Commitments to maintain tax exemption grant, investment increment over four year cycle			$ 50,000
Percentage of net operating loss deduction with regular tax						80.00%
Percentage of net operating loss deduction with alternative minimum tax						70.00%
NOL carryforwards available to offset future taxable income						$ 0
Lapse of statute of limitations						3,071	$ 283	$ 7,065
Income tax benefit (expense)						9,100	12,200	12,200
Unrecognized tax benefits (expense)						(800)	700	$ (2,000)
Liability for interest and penalties						$ 1,200	$ 2,000
Development and Installation Services
Income Tax Examination [Line Items]
Base tax rate						7.00%
Base tax rate period						10 years
Income Tax
Income Tax Examination [Line Items]
Tax exemption period			15 years
Municipal Taxes
Income Tax Examination [Line Items]
Tax exemption period			15 years
Puerto Rico
Income Tax Examination [Line Items]
Commitments to maintain tax exemption grant, percentage of resident employees			80.00%
Maximum
Income Tax Examination [Line Items]
Lapse of statute of limitations					$ 4,500