Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Receivables, allowance for doubtful accounts	$ 65,728	$ 59,424
Allowance for credit losses, current	(6,094)	(4,179)
Allowance for credit losses, noncurrent	$ (13,524)	$ (15,305)
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	160,000,000	160,000,000
Common stock, shares issued (in shares)	95,065,638	95,065,638
Common stock, shares outstanding (in shares)	55,537,836	55,535,554
Treasury stock, shares (in shares)	39,527,802	39,530,084