Employee Benefits (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Funded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions				$ 2.0
Defined Benefit Plan, Curtailments				11.2	$ 0.0
Unfunded Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension Contributions				1.8
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year				2.6
Other Postretirement Benefit Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Curtailments	[1]	$ 0.0	$ 0.4	0.0	0.4
Defined Benefit Plans, Estimated Future Employer Contributions in Current Fiscal Year				0.2
Continuing Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Postretirement Benefit Expense		$ 11.5	4.1	$ 13.2	6.1
Discontinued Operations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Postretirement Benefit Expense			$ 1.1		$ 1.7

[1] A curtailment is recognized immediately when there is a significant reduction in, or an elimination of, defined benefit accruals for current employees' future services. These expenses are included on the Condensed Consolidated Statements of Operations within "General and administrative" expense for the three and six months ended June 30, 2015, as the expenses incurred in that period related to the Pension Plan amendment (see above), and within "Net gain (loss) from asset sales" for the three and six months ended June 30, 2014, as the expenses incurred in that period related to the Midcontinent property sales (see Note 3 - Acquisitions and Divestitures).