Future Minimum Rental Payments under Lease Commitments (Detail) $ in Thousands	Dec. 31, 2016 USD ($)
Leases [Abstract]
Capital Leases, 2017	$ 4,010
Capital Leases, 2018	4,078
Capital Leases, 2019	3,998
Capital Leases, 2020	3,339
Capital Leases, 2021	3,429
Capital Leases, Later years	18,626
Capital Leases, Total minimum rental	37,480
Less: Amount representing interest	(14,034)
Present value of minimum rental commitments	23,446
Less: Current portion of capital lease obligations	(1,661)
Long-term portion of capital lease obligations	21,785
Operating Leases, 2017	66,086
Operating Leases, 2018	55,248
Operating Leases, 2019	46,943
Operating Leases, 2020	37,611
Operating Leases, 2021	32,060
Operating Leases, Later years	132,085
Operating Leases, Total minimum rental	$ 370,033