Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2012

Compensation and Retirement Disclosure [Abstract]

Schedule of Components of Net Periodic Benefit Cost

The components of net periodic benefit cost and other amounts recognized in other comprehensive income were as follows:

	Pension benefits									Other retirement benefits
($ in millions)	2012			2011			2010			2012			2011			2010
Net periodic benefit cost:
Service cost	$	8.5		$	8.9		$	8.6		$	1.3		$	1.2		$	1.1
Interest cost	15.5			16.0			15.7			1.0			1.0			0.8
Expected return on assets	(16.4		)	(16.0		)	(14.7		)	—			—			—
Amortization of prior service (credit) cost	(1.4		)	(1.5		)	(1.1		)	0.1			0.1			0.1
Amortization of transition obligation	0.1			0.1			0.1			—			—			—
Amortization of actuarial loss (gain)	8.5			6.0			5.6			—			—			(0.1		)
Curtailment	—			(0.2		)	—			—			—			—
Settlement effects	—			0.8			—			—			—			—
Net periodic benefit cost	$	14.8		$	14.1		$	14.2		$	2.4		$	2.3		$	1.9
Other changes in plan assets and benefit obligations recognized in other comprehensive income, pre-tax:
Net loss (gain) arising during period	$	17.3		$	46.7		$	9.1		$	2.1		$	1.3		$	(1.5	)
Prior service credit arising during period	—			—			(5.2		)	—			—			—
Amortization of prior service credit (cost)	1.4			1.5			1.1			(0.1		)	(0.1		)	(0.1		)
Amortization of transition obligation	(0.1		)	(0.1		)	(0.1		)	—			—			—
Amortization of actuarial (loss) gain	(8.5		)	(6.0		)	(5.6		)	—			—			0.1
Curtailment	—			0.2			—			—			0.4			—
Settlement effects	—			(0.8		)	—			—			—			—
Total recognized in other comprehensive income	$	10.1		$	41.5		$	(0.7	)	$	2.0		$	1.6		$	(1.5	)
Total recognized in net periodic benefit cost and other comprehensive income	$	24.9		$	55.6		$	13.5		$	4.4		$	3.9		$	0.4

Net periodic benefit cost by geographic location is as follows:

	Pension benefits						Other retirement benefits
	2012		2011		2010		2012		2011		2010
U.S. plans	$	12.0	$	11.4	$	11.7	$	2.4	$	2.3	$	1.9
International plans	2.8		2.7		2.5		—		—		—
Net periodic benefit cost	$	14.8	$	14.1	$	14.2	$	2.4	$	2.3	$	1.9

Schedule of Changes in Projected Benefit Obligation, Fair Value of Plan Assets and Funded Status

The following table presents the changes in the projected benefit obligation and the fair value of plan assets, as well as the funded status of the plans:

	Pension benefits						Other retirement benefits
($ in millions)	2012			2011			2012			2011
Change in benefit obligation:
Benefit obligation, January 1	$	(319.9	)	$	(283.5	)	$	(21.7	)	$	(18.1	)
Service cost	(8.5		)	(8.9		)	(1.3		)	(1.2		)
Interest cost	(15.5		)	(16.0		)	(1.0		)	(1.0		)
Participants' contributions	—			—			(0.5		)	(0.3		)
Actuarial (loss) gain	(32.4		)	(27.3		)	(2.1		)	(1.4		)
Amendments/transfers in	(0.3		)	(0.4		)	—			—
Benefits/expenses paid	15.3			16.4			0.6			0.7
Curtailment	—			(0.8		)	—			(0.4		)
Foreign currency translation	(1.9		)	0.6			—			—
Benefit obligation, December 31	$	(363.2	)	$	(319.9	)	$	(26.0	)	$	(21.7	)
Change in plan assets:
Fair value of assets, January 1	$	213.3		$	212.3		$	—		$	—
Actual return on assets	32.3			(2.8		)	—			—
Employer contribution	19.8			20.4			0.1			0.4
Participants' contribution	—			—			0.5			0.3
Benefits/expenses paid	(15.3		)	(16.4		)	(0.6		)	(0.7		)
Foreign currency translation	0.9			(0.2		)	—			—
Fair value of assets, December 31	$	251.0		$	213.3		$	—		$	—
Funded status at end of year	$	(112.2	)	$	(106.6	)	$	(26.0	)	$	(21.7	)

Schedule of Amounts Recognized in Balance Sheet

Amounts recognized in the balance sheet were as follows:

	Pension benefits						Other retirement benefits
($ in millions)	2012			2011			2012			2011
Current liabilities	$	(1.6	)	$	(1.2	)	$	(1.2	)	$	(1.1	)
Noncurrent liabilities	(110.6		)	(105.4		)	(24.8		)	(20.6		)
	$	(112.2	)	$	(106.6	)	$	(26.0	)	$	(21.7	)

Schedule of Amounts Recognized in Other Comprehensive Income (Loss)

The amounts in accumulated other comprehensive loss, pre-tax, consisted of:

	Pension benefits						Other retirement benefits
($ in millions)	2012			2011			2012		2011
Net actuarial loss (gain)	$	140.0		$	131.3		$	2.3	$	0.2
Transition obligation	0.4			0.4			—		—
Prior service (credit) cost	(8.8		)	(10.2		)	—		0.1
Total	$	131.6		$	121.5		$	2.3	$	0.3

Schedule of Expected Benefit Payments

Benefit payments expected to be paid under our defined benefit pension plans in the next ten years are as follows:

($ in millions)	Domestic Plans		International Plans		Total
2013	$	19.0	$	1.6	$	20.6
2014	20.0		1.5		21.5
2015	20.9		1.6		22.5
2016	22.5		1.9		24.4
2017	25.1		2.4		27.5
2018 to 2022	136.0		55.3		191.3
	$	243.5	$	64.3	$	307.8

Schedule of Assumptions Used

Weighted average assumptions used to determine net periodic benefit cost were as follows:

	Pension benefits						Other retirement benefits
	2012		2011		2010		2012		2011		2010
Discount rate	4.78	%	5.55	%	5.92	%	4.50	%	5.25	%	5.25	%
Rate of compensation increase	4.29	%	4.33	%	4.36	%	—		—		—
Long-term rate of return on assets	7.37	%	7.59	%	7.60	%	—		—		—

Weighted average assumptions used to determine the benefit obligations were as follows:

	Pension benefits				Other retirement benefits
	2012		2011		2012		2011
Discount rate	4.07	%	4.87	%	3.50	%	4.50	%
Rate of compensation increase	4.39	%	4.33	%	—		—

Schedule of Allocation of Plan Assets

The following are our target asset allocations and acceptable allocation ranges:

	Target allocation	Allocation range
Equity securities	65%	60%-70%
Debt securities	35%	30%-40%
Other	—%	0%-5%

The weighted average asset allocations by asset category for our pension plans, at December 31, were as follows:

	2012		2011
Equity securities	65	%	68	%
Debt securities	34	%	31	%
Other	1	%	1	%
	100	%	100	%

The following tables present the fair value of our pension plan assets, utilizing the fair value hierarchy discussed in Note 13, Fair Value Measurements:

	Balance at
	December 31,		Basis of Fair Value Measurements
($ in millions)	2012		Level 1		Level 2		Level 3
Equity securities:
Indexed mutual funds	$	111.4	$	111.4	$	—	$	—
International mutual funds	49.6		49.6		—		—
Fixed income securities:
Mutual funds	83.8		83.8		—		—
Insurance contract	1.3		—		1.3		—
Balanced mutual fund	4.9		4.9		—		—
	$	251.0	$	249.7	$	1.3	$	—

	Balance at
	December 31,		Basis of Fair Value Measurements
($ in millions)	2011		Level 1		Level 2		Level 3
Cash	$	0.2	$	0.2	$	—	$	—
Equity securities:
Indexed mutual funds	102.2		102.2		—		—
International mutual funds	40.0		40.0		—		—
Fixed income securities:
Mutual funds	65.6		65.6		—		—
Insurance contract	1.3		—		1.3		—
Balanced mutual fund	4.0		4.0		—		—
	$	213.3	$	212.0	$	1.3	$	—