Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.19.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Commitment And Contingencies [Line Items]    
Rental expense included in operating expenses $ 20.2 $ 20.3
Minimum [Member]    
Commitment And Contingencies [Line Items]    
Operating lease expiration period 10 years  
Operating lease renewal period 1 year  
Maximum [Member]    
Commitment And Contingencies [Line Items]    
Operating lease expiration period 25 years  
Operating lease renewal period 5 years