Future Minimum Rental Payments under Lease Commitments (Detail) $ in Thousands	Dec. 31, 2018 USD ($)
Leases [Abstract]
Capital Leases, 2019	$ 3,996
Capital Leases, 2020	3,345
Capital Leases, 2021	3,227
Capital Leases, 2022	3,508
Capital Leases, 2023	3,624
Capital Leases, Later years	12,070
Capital Leases, Total minimum rental	29,770
Less: Amount representing interest	(9,829)
Present value of minimum rental commitments	19,941
Less: Current portion of capital lease obligations	(2,128)
Long-term portion of capital lease obligations	17,813
Operating Leases, 2019	72,353
Operating Leases, 2020	59,492
Operating Leases, 2021	48,891
Operating Leases, 2022	35,233
Operating Leases, 2023	28,839
Operating Leases, Later years	123,039
Operating Leases, Total minimum rental	$ 367,847