Guarantee of Securities of Subsidiaries Guarantee of Securities of Subsidiaries Statements of Cash Flows (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Cash Flows
Net Cash Provided by (Used in) Operating Activities	$ 135.8	$ 129.3
Investing Activities:
Capital expenditures	(66.1)	(70.6)
Proceeds from sale of operating assets	0.1	1.0
Proceeds from insurance and other recoveries	0	1.4
Advances to affiliates	(1.3)	0
Investment in consolidated subsidiary		0
Investment in unconsolidated affiliates	(19.7)	0
Distribution from unconsolidated affiliate	9.0	0
Net cash used in investing activities	(78.0)	(68.2)
Financing Activities:
Proceeds from borrowings on revolving credit agreement	155.0	263.0
Repayment of borrowings on revolving credit agreement	(205.0)	(195.0)
Contribution from parent		0
Principal payment of capital lease obligation	(0.1)	0
Advances from affiliates	0	(0.4)
Distributions paid	(24.8)	(128.3)
Capital contributions from noncontrolling interests	7.8	0
Distributions paid to noncontrolling interests	(7.1)	0
Net cash used in financing activities	(74.2)	(60.7)
Increase (decrease) in cash and cash equivalents	(16.4)	0.4
Cash and cash equivalents at beginning of period	28.5	3.9
Cash and cash equivalents at end of period	12.1	4.3
Parent Guarantor
Statement of Cash Flows
Net Cash Provided by (Used in) Operating Activities	7.4	9.4
Investing Activities:
Capital expenditures	0	0
Proceeds from sale of operating assets	0	0
Proceeds from insurance and other recoveries		0
Advances to affiliates	17.3	119.2
Investment in consolidated subsidiary		0
Investment in unconsolidated affiliates	0
Distribution from unconsolidated affiliate	0
Net cash used in investing activities	17.3	119.2
Financing Activities:
Proceeds from borrowings on revolving credit agreement	0	0
Repayment of borrowings on revolving credit agreement	0	0
Contribution from parent		0
Principal payment of capital lease obligation	0
Advances from affiliates	0	(0.4)
Distributions paid	(24.8)	(128.3)
Capital contributions from noncontrolling interests	0
Distributions paid to noncontrolling interests	0
Net cash used in financing activities	(24.8)	(128.7)
Increase (decrease) in cash and cash equivalents	(0.1)	(0.1)
Cash and cash equivalents at beginning of period	0.2	0.1
Cash and cash equivalents at end of period	0.1	0
Subsidiary Issuer
Statement of Cash Flows
Net Cash Provided by (Used in) Operating Activities	(33.5)	(27.0)
Investing Activities:
Capital expenditures	0	(0.3)
Proceeds from sale of operating assets	0	0
Proceeds from insurance and other recoveries		0
Advances to affiliates	(8.3)	(31.3)
Investment in consolidated subsidiary		(12.0)
Investment in unconsolidated affiliates	0
Distribution from unconsolidated affiliate	0
Net cash used in investing activities	(8.3)	(43.6)
Financing Activities:
Proceeds from borrowings on revolving credit agreement	0	0
Repayment of borrowings on revolving credit agreement	0	0
Contribution from parent		0
Principal payment of capital lease obligation	0
Advances from affiliates	37.8	71.6
Distributions paid	0	0
Capital contributions from noncontrolling interests	0
Distributions paid to noncontrolling interests	0
Net cash used in financing activities	37.8	71.6
Increase (decrease) in cash and cash equivalents	(4.0)	1.0
Cash and cash equivalents at beginning of period	9.2	1.0
Cash and cash equivalents at end of period	5.2	2.0
Non-Guarantor Subsidiaries
Statement of Cash Flows
Net Cash Provided by (Used in) Operating Activities	161.9	146.9
Investing Activities:
Capital expenditures	(66.1)	(70.3)
Proceeds from sale of operating assets	0.1	1.0
Proceeds from insurance and other recoveries		1.4
Advances to affiliates	(56.4)	(190.8)
Investment in consolidated subsidiary		0
Investment in unconsolidated affiliates	(19.7)
Distribution from unconsolidated affiliate	9.0
Net cash used in investing activities	(133.1)	(258.7)
Financing Activities:
Proceeds from borrowings on revolving credit agreement	155.0	263.0
Repayment of borrowings on revolving credit agreement	(205.0)	(195.0)
Contribution from parent		12.0
Principal payment of capital lease obligation	(0.1)
Advances from affiliates	8.3	31.3
Distributions paid	0	0
Capital contributions from noncontrolling interests	7.8
Distributions paid to noncontrolling interests	(7.1)
Net cash used in financing activities	(41.1)	111.3
Increase (decrease) in cash and cash equivalents	(12.3)	(0.5)
Cash and cash equivalents at beginning of period	19.1	2.8
Cash and cash equivalents at end of period	6.8	2.3
Eliminations
Statement of Cash Flows
Net Cash Provided by (Used in) Operating Activities	0	0
Investing Activities:
Capital expenditures	0	0
Proceeds from sale of operating assets	0	0
Proceeds from insurance and other recoveries		0
Advances to affiliates	46.1	102.9
Investment in consolidated subsidiary		12.0
Investment in unconsolidated affiliates	0
Distribution from unconsolidated affiliate	0
Net cash used in investing activities	46.1	114.9
Financing Activities:
Proceeds from borrowings on revolving credit agreement	0	0
Repayment of borrowings on revolving credit agreement	0	0
Contribution from parent		(12.0)
Principal payment of capital lease obligation	0
Advances from affiliates	(46.1)	(102.9)
Distributions paid	0	0
Capital contributions from noncontrolling interests	0
Distributions paid to noncontrolling interests	0
Net cash used in financing activities	(46.1)	(114.9)
Increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents at beginning of period	0	0
Cash and cash equivalents at end of period	$ 0	$ 0