Schedule of Committed Credit Facilities Additional Information (Detail)	12 Months Ended	24 Months Ended
	Dec. 31, 2018	Dec. 31, 2018
Uncommitted Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period		0.74%
Uncommitted Credit Facility [Member] | Maximum
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period		6.60%
Bank Overdrafts [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period	3.10%
Bank Overdrafts [Member] | Maximum
Line of Credit Facility [Line Items]
Line of Credit Facility, Interest Rate During Period	3.18%
Revolving Credit Facility Maturing 2018
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.00%