Segment, Customer and Geographic Information - Schedule of Revenues and Total Trade Accounts Receivable Represents Customer Accounted for 10% or More Percentage (Detail) - Customer Concentration Risk [Member]	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Sales [Member] | Customer A [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Customer A	11.00%	0.00%
Trade Accounts Receivable [Member] | Customer A [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Customer A	15.00%		4.00%
Trade Accounts Receivable [Member] | Customer B [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Customer A	7.00%		12.00%