Other Assets - Schedule of Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Overfunded pension plans	$ 70,792	$ 4,343
Cash surrender value of life insurance contracts	45,216	43,425
Other(a)	33,942	79,944
Total	$ 149,950	$ 127,712