Income Taxes - Summary of Tax Years that Remain Subject to Examination by Major Jurisdiction (Detail)	6 Months Ended
	Jun. 30, 2018
Foreign Tax Authority [Member] | Canada [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Foreign Tax Authority [Member] | France [Member]
Income Tax Examination [Line Items]
Examination in progress	2012
Foreign Tax Authority [Member] | Philippines [Member]
Income Tax Examination [Line Items]
Examination in progress	2016
Minimum [Member] | United States - Federal [Member] | United States [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2014
Minimum [Member] | United States - State [Member] | United States [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2013
Examination in progress	2014
Minimum [Member] | Foreign Tax Authority [Member] | Canada [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2010
Examination in progress	2014
Minimum [Member] | Foreign Tax Authority [Member] | Germany [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2016
Examination in progress	2011
Minimum [Member] | Foreign Tax Authority [Member] | France [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2015
Minimum [Member] | Foreign Tax Authority [Member] | United Kingdom [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2016
Minimum [Member] | Foreign Tax Authority [Member] | Philippines [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2015
Maximum [Member] | United States - Federal [Member] | United States [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Maximum [Member] | United States - State [Member] | United States [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Examination in progress	2016
Maximum [Member] | Foreign Tax Authority [Member] | Canada [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2013
Examination in progress	2016
Maximum [Member] | Foreign Tax Authority [Member] | Germany [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Examination in progress	2015
Maximum [Member] | Foreign Tax Authority [Member] | France [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Maximum [Member] | Foreign Tax Authority [Member] | United Kingdom [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017
Maximum [Member] | Foreign Tax Authority [Member] | Philippines [Member]
Income Tax Examination [Line Items]
Examinations not yet initiated	2017