Investments and other assets - Components of Investments and Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Investments, All Other Investments [Abstract]
Cash value life insurance	$ 52,883	$ 52,462
Equity method investments	32,067	27,650
Other equity investments	20,271	32,383
Deferred debt issuance costs	9,378	10,921
Other long-term assets	21,620	21,853
Total	$ 136,219	$ 145,269