Retirement Benefit Plans (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined benefit plan, cost recognized	$ 53,200,000	$ 47,000,000	$ 43,600,000
Other postretirement benefits payable	20,000,000	18,900,000
Prescription drug benefit subsidy, percentage	28.00%
Prescription drug subsidy, minimum claim	320
Prescription drug subsidy, maximum claim	6,500
Cash investments in time deposits	2,800,000	5,800,000
Retirement Plans [Member]
Estimated amounts of contributions expected to be paid to the plans in next fiscal year	6,100,000
Medical Plans [Member]
Estimated amounts of contributions expected to be paid to the plans in next fiscal year	$ 2,100,000