Benefit Plans (Long-Term Target Allocations Of Assets For U.S And UK Plans) (Details)	12 Months Ended
	Dec. 31, 2011
U.S. Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	100.00%
U.S. Plans [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	60.00%
U.S. Plans [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	38.00%
U.S. Plans [Member] | Real Estate And Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	2.00%
UK Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	100.00%
UK Plan [Member] | Cash And Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	4.00%
UK Plan [Member] | Equity [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	50.00%
UK Plan [Member] | Fixed Income [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	26.00%
UK Plan [Member] | Real Estate And Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan target plan asset allocations	20.00%