Debt - Schedule of Net Interest Expense (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Income Expense Net [Abstract]
Interest expense									$ 13,360	$ 14,428	$ 15,240
Interest income									(1,829)	(2,075)	(1,247)
Interest expense net of interest income									11,531	12,353	13,993
Capitalized interest									(760)	(909)	(788)
Interest expense, net	$ 2,151	$ 2,797	$ 2,672	$ 3,151	$ 2,826	$ 2,763	$ 2,863	$ 2,992	$ 10,771	$ 11,444	$ 13,205