Employee Retirement Plans (Accumulated Benefit Obligations, Amounts Recognized on Balance Sheets, and Reconciliation of AOCI) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Amount arising during the period	$ (95,200,000)	$ 133,600,000	$ (28,700,000)
Amortization of net actuarial (gain) loss included in net earnings (loss)	(300,000)	300,000	(100,000)
Amortization of prior service credit included in net earnings	(5,800,000)	(5,700,000)	(3,400,000)
Reduction of plan obligations due to elimination of reimbursement of medical costs			5,700,000
Reduction of plan obligations due to elimination of postretirement medical benefit coverage			16,900,000
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Current liabilities	(1,200,000)	(4,000,000)
Noncurrent liabilities	(161,500,000)	(106,000,000)
Total amount recognized	(162,700,000)	(110,000,000)
Amortization of:
Total	0
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Current liabilities	0	(800,000)
Noncurrent liabilities	0	(3,200,000)
Total amount recognized	0	(4,000,000)
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Accumulated other comprehensive income (loss), before Tax, beginning balance	11,000,000	15,700,000
Amount arising during the period	0	1,000,000
Amortization of prior service credit included in net earnings	(6,100,000)	(5,700,000)
Plan curtailments included in net loss	(4,900,000)	0	(12,800,000)
Accumulated other comprehensive income (loss), before Tax, ending balance	0	11,000,000	15,700,000
Actuarial Gain (Loss), net [Member] | Pension Plans, Defined Benefit [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Accumulated other comprehensive income (loss), Actuarial Gain/(Loss), net, before Tax, beginning balance	50,600,000	(80,200,000)
Amount arising during the period	(95,200,000)	132,600,000
Amortization of net actuarial (gain) loss included in net earnings (loss)	0	300,000
Plan curtailments included in net loss	0	(2,100,000)
Accumulated other comprehensive income (loss), Actuarial Gain/(Loss), net, before Tax, ending balance	(44,600,000)	50,600,000
Actuarial Gain (Loss), net [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Accumulated other comprehensive income (loss), Actuarial Gain/(Loss), net, before Tax, beginning balance	(11,600,000)	(12,600,000)
Amount arising during the period	0	1,000,000
Amortization of net actuarial (gain) loss included in net earnings (loss)	(300,000)	0
Plan curtailments included in net loss	11,900,000	0
Accumulated other comprehensive income (loss), Actuarial Gain/(Loss), net, before Tax, ending balance	0	(11,600,000)
Prior Service Credit (Cost) [Member] | Other Postretirement Benefit Plans, Defined Benefit [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Accumulated other comprehensive income (loss), Prior Service (Credit)/Cost, before Tax, beginning balance	22,600,000	28,300,000
Amount arising during the period	0	0
Amortization of prior service credit included in net earnings	(5,800,000)	(5,700,000)
Plan curtailments included in net loss	(16,800,000)	0
Accumulated other comprehensive income (loss), Prior Service (Credit)/Cost, before Tax, ending balance	0	22,600,000
Defined Benefit Plan, Termination [Member] | Actuarial Gain (Loss), net [Member] | Pension Plans, Defined Benefit [Member]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), before Tax
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	$ (3,700,000)