Share-Based Payments Non-vested (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized on nonvested awards	$ 25.7
Compensation cost not yet recognized on nonvested awards, period for recognition	2 years
RSUs and DSUs
Equity Instruments Other than Options, Nonvested [Roll Forward]
Non-vested awards outstanding at the beginning of the period (in shares)	0.7
Granted (in shares)	0.3
Vested (in shares)	(0.2)
Forfeited (in shares)	(0.1)
Non-vested awards outstanding at the end of the period (in shares)	0.7
Non-vested, weighted-average grant date fair value at the beginning of the period (in dollars per unit)	$ 42.08
Granted, weighted-average grant date fair value (in dollars per unit)	$ 58.09
Vested, weighted-average grant date fair value (in dollars per unit)	$ 41.30
Forfeited, weighted-average grant date fair value (in dollars per unit)	$ 43.82
Non-vested, weighted-average grant date fair value at the end of the period (in dollars per unit)	$ 47.75
PUs
Equity Instruments Other than Options, Nonvested [Roll Forward]
Non-vested awards outstanding at the beginning of the period (in shares)	1.0
Granted (in shares)	0		0.7
Vested (in shares)	(0.5)
Forfeited (in shares)	0
Non-vested awards outstanding at the end of the period (in shares)	0.5	1.0
Non-vested, weighted-average grant date fair value at the beginning of the period (in dollars per unit)	$ 2.87
Granted, weighted-average grant date fair value (in dollars per unit)	$ 0.00
Vested, weighted-average grant date fair value (in dollars per unit)	$ 6.29
Forfeited, weighted-average grant date fair value (in dollars per unit)	$ 0.00
Non-vested, weighted-average grant date fair value at the end of the period (in dollars per unit)	$ 3.22	$ 2.87
Equity instruments other than options, vested in period, fair value	2.8	6.9	7.3
Performance shares (PSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Intrinsic Value, Amount Per Share	$ 60.33
Equity Instruments Other than Options, Nonvested [Roll Forward]
Non-vested awards outstanding at the beginning of the period (in shares)	0.2
Granted (in shares)	0.2	0.2
Vested (in shares)	0
Forfeited (in shares)	0
Non-vested awards outstanding at the end of the period (in shares)	0.4	0.2
Non-vested, weighted-average grant date fair value at the beginning of the period (in dollars per unit)	$ 43.10
Granted, weighted-average grant date fair value (in dollars per unit)	$ 58.69	$ 43.10
Vested, weighted-average grant date fair value (in dollars per unit)	$ 0.00
Forfeited, weighted-average grant date fair value (in dollars per unit)	$ 0.00
Non-vested, weighted-average grant date fair value at the end of the period (in dollars per unit)	$ 50.49	$ 43.10
RSUs, DSUs, PUs and PSUs
Equity Instruments Other than Options, Nonvested [Roll Forward]
Equity instruments other than options, vested in period, fair value	$ 12.9	$ 10.2	$ 9.4