Lease Agreements - Additional Information (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($) integer
Schedule of Operating Leases [Line Items]
Number of properties where non-cancelable long-term leases are in effect | integer	24
2018	$ 106,578
2019	105,698
2020	66,108
2021	12,635
2022	11,920
Thereafter	36,674
Total	$ 339,613
Minimum
Schedule of Operating Leases [Line Items]
Operating leases, term of contract (in years)	1 year
Maximum
Schedule of Operating Leases [Line Items]
Operating leases, term of contract (in years)	10 years