Description of Business and Summary of Significant Accounting Policies - Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Liabilities [Abstract]
Pension and postretirement benefits liability	$ 34,763	$ 37,988
Straight-line lease liability	95,078	89,959
Deferred compensation liability	25,055	22,204
Other	949	885
Total other liabilities	$ 155,845	$ 151,036