Short and Long-Term Debt - Short-Term Debt Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Line Items]
Restricted Cash and Cash Equivalents	$ 400	$ 300
Gain (Loss) on Extinguishment of Debt	0	$ 0	$ (1,494)
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 600,000
Debt, Weighted Average Interest Rate	1.15%
Line of Credit Facility, Remaining Borrowing Capacity	$ 385,500
Federal Funds Effective Swap Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Daily Libor Rate | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.00%
Minimum | BASE or LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.00%
Maximum | BASE or LIBOR | Revolving Credit Facility
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Senior Revolving Credit Facility Maturing in 2023 | Overnight Bank Funding Rate
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.50%
Multi-currency Notes Due in 2031
Line of Credit Facility [Line Items]
Debt Instrument, Covenant, Fixed Charges Coverage Ratio, Minimum	1.50
Debt Instrument, Covenant, Consolidated Leverage Ratio, Maximum	3.50
Debt Instrument, Covenant, Consolidated Leverage Ratio In Period Of Acquisition, Maximum	4.00
Notes Payable, Other Payables [Member] | Multi-currency Notes Due in 2031
Line of Credit Facility [Line Items]
Additional Senior Notes Available for Request	$ 150,000
Notes Payable, Other Payables [Member] | Master Note Facility Due in 2022
Line of Credit Facility [Line Items]
Additional Senior Notes Available for Request	$ 150,000