Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable, allowance	$ 3.6	$ 1.9
Restricted cash, current	29.5	32.0
Accumulated depreciation and amortization, property	577.4	788.6
Restricted cash, noncurrent	$ 64.4	$ 70.5
Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000	10,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Series A Junior Participating Preferred Stock [Member]
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	0	0
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, shares issued (in shares)	337,978	336,938
Common stock, shares outstanding (in shares)	337,978	336,938
Class B Common Stock [Member]
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	3	3
Common stock, shares issued (in shares)	3	3
Common stock, shares outstanding (in shares)	3	3