CONSOLIDATED STATEMENT OF STOCKHOLDERS' DEFICIENCY (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Shares withheld for withholding taxes (in shares)	82,740	22,328
Shares withheld for withholding taxes, weighted average price per share (in dollars per share)	$ 34.40
Shares withheld for withholding taxes	$ 2.8	$ 0.7
Treasury Stock [Member]
Shares withheld for withholding taxes (in shares)	82,740	22,328
Treasury Stock [Member] | Class A Common Stock [Member]
Shares withheld for withholding taxes (in shares)	82,740	22,328
Shares withheld for withholding taxes, weighted average price per share (in dollars per share)	$ 34.40	$ 33.54
Shares withheld for withholding taxes	$ 2.8	$ 0.7