XML 39 R29.htm IDEA: XBRL DOCUMENT v3.21.1
Long-Term Debt and Financing Arrangements - Additional Information (Detail) - USD ($)
Jul. 01, 2017
Mar. 31, 2021
Dec. 31, 2020
Mar. 31, 2020
Standby Letters of Credit [Member]        
Line Of Credit Facility [Line Items]        
Outstanding letters of credit       $ 37,400
Revolving Credit Facility [Member] | Bank Revolving Line Of Credit [Member]        
Line Of Credit Facility [Line Items]        
Unused and available borrowings under bank revolving line of credit and credit agreement   $ 312,600,000 $ 312,300,000  
Credit Agreement [Member]        
Line Of Credit Facility [Line Items]        
Amount of credit agreement $ 350,000      
Line of Credit Facility, Expiration Date Jul. 01, 2022