Revenue Recognition - Summary of Revenues by Type of Item Sold (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total	100.00%	100.00%	100.00%	100.00%
Revenue Recognized Point In Time
Disaggregation Of Revenue [Line Items]
Revenue on products with an alternative use	88.00%	88.00%	88.00%	89.00%
Revenue Recognized Over Time
Disaggregation Of Revenue [Line Items]
Revenue on products with no alternative use	12.00%	12.00%	12.00%	11.00%