Employee Benefit Plans (Health-Care Cost Trend Rates Used To Determine The Benefit Obligation) (Details) (Postretirement Medical Plan [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Health-care cost trend rate assumed for next year	7.40%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	4.50%
Year that the rate reaches the ultimate trend rate	2027
Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	(160)
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	(3,199)
Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	179
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	3,579