Stock-Based and Other Incentive Compensation - Restricted Stock Units (Details) (Restricted Stock Units, USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock Units
Number of Restricted Stock Units (in shares):
Unvested units outstanding at the beginning of the period	4,815,000
Granted	2,723,000
Vested	(1,115,000)
Cancelled	(1,211,000)
Unvested units outstanding at the end of the period	5,212,000	4,815,000
Weighted Average Grant Date Fair Value (in dollars per share):
Unvested units outstanding at the beginning of the period	$ 10.53
Granted	$ 12.49	$ 12.23	$ 8.52
Vested	$ 12.61
Cancelled	$ 9.13
Unvested units outstanding at the end of the period	$ 11.93	$ 10.53
Stock-based compensation expense recognized	$ 19.7	$ 19.7	$ 15.2
Tax benefit recognized related to stock based compensation expenses	7.2	7.4	5.7
Unrecognized stock-based compensation expense relating to unvested awards that will be amortized	40.5
Weighted-average period of amortization	2 years
Fair value at vesting date	$ 11.0	$ 14.3	$ 8.6