Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 19,489	$ 22,691
Unamortized deferred financing costs, current	1,635	920
Unamortized deferred financing costs, noncurrent	$ 671	$ 1,062
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series Y preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Series Y preferred stock, shares authorized (in shares)	350,000	350,000
Series Y preferred stock, shares issued (in shares)	0	0
Series Y preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.10	$ 0.10
Common stock, shares authorized (in shares)	220,000,000	220,000,000
Common stock, shares issued (in shares)	30,684,387	30,515,334
Common stock, shares outstanding (in shares)	30,684,387	30,515,334