CONSOLIDATED BALANCE SHEETS Balance Sheet Parenthicals - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts Receivable	$ 3.4	$ 2.7
Restricted Cash and Cash Equivalents, Current	4.3	1.5
Restricted Cash and Cash Equivalents, Noncurrent	$ 0.9	$ 1.2
Series A junior participating preferred stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Series B Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.00	$ 0.00
Preferred Stock, Shares Authorized	0	0
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Class A Common Stock (Shares) [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Outstanding	357,469,000	356,824,000
Common Stock, Shares, Issued	357,469,000	356,824,000
Class B Common Stock (Shares) [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	3,000	3,000
Common Stock, Shares, Outstanding	3,000	3,000
Common Stock, Shares, Issued	3,000	3,000