Retirement and Postretirement Plans (Tables)

12 Months Ended

Dec. 31, 2011

Retirement and Postretirement Plans

Schedule of changes in projected benefit obligations and fair value of plan assets and funded status of plan assets

The following tables set forth the obligations and funded status, assumptions, plan assets and cash flows associated with the various pension plans at December 31, 2011 and 2010:

	Pension Benefits
Millions	2011			2010
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	$	110.2		$	117.1
Service cost	.8			.8
Interest cost	5.2			6.0
Settlement gain	(.6		)	(2.2		)
Special termination benefit cost	.8			1.9
Assumption changes	7.7			6.6
Actuarial (gain) loss	(.3		)	(1.5		)
Benefits and expenses paid with plan assets, net of participant contributions	(8.4		)	(15.9		)
Benefits paid directly by OneBeacon	(2.4		)	(2.6		)
Projected benefit obligation at end of year	$	113.0		$	110.2
Change in plan assets:
Fair value of plan assets at beginning of year	$	133.0		$	130.2
Actual return on plan assets	(3.8		)	18.7
Benefits and expenses paid, net of participant contributions	(8.4		)	(15.9		)
Fair value of plan assets at end of year	$	120.8		$	133.0
Funded status at end of year	$	7.8		$	22.8

Schedule of amounts recorded in the financial statements

Amounts recognized in the financial statements as of December 31, 2011 and 2010 consist of:

	Pension Benefits
Millions	2011			2010
Net balance recorded in other assets	$	34.3		$	50.3
Net balance recorded in other liabilities	(26.5		)	(27.5		)
Net amount accrued in the financial statements	$	7.8		$	22.8

Information for the Non-qualified Plan, which had accumulated benefit obligations in excess of plan assets

Information for the Non-qualified Plan, which had accumulated benefit obligations in excess of plan assets, was as follows:

	December 31,
Millions	2011		2010
Projected benefit obligation	$	26.5	$	27.5
Accumulated benefit obligation	$	26.5	$	27.5
Fair value of plan assets	$	—	$	—

Information for the Qualified Plan, which had accumulated benefit obligations less than plan assets

Information for the Qualified Plan, which had accumulated benefit obligations less than plan assets, was as follows:

	December 31,
Millions	2011		2010
Projected benefit obligation	$	86.5	$	82.7
Accumulated benefit obligation	$	86.5	$	82.7
Fair value of plan net assets (1)	$	120.8	$	133.0

(1)Includes receivables related to securities sold, interest and dividends as well as payables related to securities purchased.

Schedule of amount recognized in accumulated other comprehensive income (loss) on a pre-tax basis and before noncontrolling interest

The amounts recognized in accumulated other comprehensive income (loss) on a pre-tax basis and before noncontrolling interest for the years ended December 31, 2011 and 2010 were as follows:

	December 31,
Millions	2011			2010
Accumulated other comprehensive income (loss) beginning balance	$	.5		$	(8.5	)
Increase (decrease) in accumulated other comprehensive income (loss):
Amortization of net actuarial losses recognized during the year	.5			.6
Net actuarial (losses) gains occurring during the year(1)	(18.2		)	8.4
Other adjustments	.5			—
Accumulated other comprehensive (loss) income ending balance	$	(16.7	)	$	.5

(1)Primarily relates to investment results relating to the overfunded status of the Plans.

Schedule of components of net periodic benefit cost (income)

The components of net periodic benefit cost (income) for the years ended December 31, 2011, 2010 and 2009 were as follows:

	Year Ended December 31,
Millions	2011			2010			2009
Service cost	$	.8		$	.8		$	.5
Interest cost	5.2			6.0			6.5
Expected return on plan assets	(7.6		)	(7.3		)	(6.3		)
Amortization of unrecognized loss	.5			.6			1.6
Net periodic pension cost (income) before settlements, curtailments and special termination benefits	(1.1		)	.1			2.3
Settlement gain	.5			(.1		)	—
Special termination benefits expense(1)	.8			1.9			1.2
Total net periodic benefit cost	$	.2		$	1.9		$	3.5

(1)Special termination benefits represent additional payments made from the Qualified Plan to certain vested participants when their employment was terminated due to a reduction in force.

Schedule of fair value of the Plan assets and their related inputs

The fair value of the Qualified Plan’s assets and their related inputs at December 31, 2011 by asset category were as follows:

	December 31, 2011								December 31, 2010
Millions	Fair Value		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs		Fair Value		Level 1 Inputs		Level 2 Inputs		Level 3 Inputs
Fixed maturity investments	$	2.4	$	—	$	2.4	$	—	$	.5	$	—	$	.5	$	—
Common equity securities	72.2		72.2		—		—		74.5		74.5		—		—
Convertible fixed maturities	42.8		—		42.8		—		55.7		—		55.7		—
Cash and short-term investments	3.1		3.1		—		—		2.0		2.0		—		—
Total	$	120.5	$	75.3	$	45.2	$	—	$	132.7	$	76.5	$	56.2	$	—

There were no transfers between Levels 1, 2 or 3 during the years ended December 31, 2011 or 2010.

The Qualified Plan’s asset allocations at December 31, 2011 and 2010, by asset category were as follows:

	Plan Assets at December 31,
Asset Category	2011		2010
Fixed maturity investments	2.0	%	.4	%
Common equity securities	59.9		56.1
Convertible fixed maturities	35.5		42.0
Cash and short-term investments	2.6		1.5
Total	100.0	%	100.0	%

Schedule of expected future benefit payments

The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid:

Millions	Expected Benefit Payments
2012	$	4.6
2013	5.0
2014	5.3
2015	5.7
2016	6.0
2017—2021	34.0