Future Minimum Rental Commitments for All Non-Cancelable Leases (Detail) $ in Thousands	Dec. 31, 2017 USD ($)
Commitments and Contingencies Disclosure [Abstract]
2018, Operating Leases	$ 45,064
2019, Operating Leases	40,265
2020, Operating Leases	35,124
2021, Operating Leases	31,298
2022, Operating Leases	26,668
Thereafter, Operating Leases	58,982
Total future minimum rental commitments, Operating Leases	237,401
2018, Capital Leases	826
2019, Capital Leases	828
2020, Capital Leases	831
2021, Capital Leases	833
2022, Capital Leases	836
Thereafter, Capital Leases	4,343
Total future minimum rental commitments, Capital Leases	8,497
Less - amounts representing interest, Capital Leases	(3,060)
Total principal payable on capital leases	5,437
2018, Operating and Capital Leases	45,890
2019, Operating and Capital Leases	41,093
2020,Operating and Capital Leases	35,955
2021, Operating and Capital Leases	32,131
2022, Operating and Capital Leases	27,504
Thereafter, Operating and Capital Leases	63,325
Total future minimum rental commitments, Operating and Capital Leases	$ 245,898