Employee Benefit Plans (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Amounts recognized in other comprehensive income (loss):
Prior service costs	$ (2.6)	$ (3.5)
Actuarial loss	(212.0)	(176.2)
Subtotal	(214.6)	(179.7)
Deferred taxes	78.6	66.2
Net amount recognized	(136.0)	(113.5)
Changes recognized in other comprehensive income (loss):
Current year actuarial loss	44.4	25.8
Effect of exchange rates	(0.4)	0.3
Amortization of prior service (costs) credits	(0.9)	(0.5)
Amortization of actuarial loss	(8.2)	(6.5)
Total recognized in other comprehensive income	34.9	19.1
Total recognized in net periodic benefit cost and other comprehensive income (loss)	48.2	29.2
Other Benefits [Member]
Amounts recognized in other comprehensive income (loss):
Prior service costs	12.7	14.7
Actuarial loss	(20.8)	(19.8)
Subtotal	(8.1)	(5.1)
Deferred taxes	3.1	1.9
Net amount recognized	(5.0)	(3.2)
Changes recognized in other comprehensive income (loss):
Current year prior service costs		(0.1)
Current year actuarial loss	2.3	2.4
Amortization of prior service (costs) credits	1.9	1.9
Amortization of actuarial loss	(1.2)	(1.3)
Total recognized in other comprehensive income	3.0	2.9
Total recognized in net periodic benefit cost and other comprehensive income (loss)	$ 4.0	$ 3.6