Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows [Abstract]
Cash Flows from (used in) Operating Activities:	$ 26.8	$ (29.4)
Cash Flows from Investing Activities:
Capital expenditures for property, plant and equipment	(8.6)	(8.5)
Proceeds from investment tax credits and grants related to Port Allen Solar Farm	0	3.5
Proceeds from disposal of property and other assets	5.1	0.4
Proceeds from disposals related to 1031 commercial property transactions	4.6	69.4
Payments for purchases of investments in affiliates	(11.1)	(5.0)
Proceeds from investments in affiliates	33.4	0.5
Change in restricted cash associated with 1031 transactions	0	(2.8)
Net cash provided by investing activities	23.4	57.5
Cash Flows from Financing Activities:
Proceeds from issuances of long-term debt	20.0	45.0
Payments of long-term debt and deferred financing costs	(68.5)	(11.0)
Proceeds (payments) from line-of-credit agreements, net	3.3	(58.0)
Dividends paid	(3.6)	(1.9)
Proceeds from issuance (repurchase) of capital stock and other, net	(0.8)	0
Net cash used in financing activities	(49.6)	(25.9)
Cash and Cash Equivalents:
Net increase for the period	0.6	2.2
Balance, beginning of period	2.8	3.3
Balance, end of period	3.4	5.5
Other Cash Flow Information:
Interest paid	(9.7)	(9.8)
Income taxes paid	0	(3.5)
Other Non-cash Information:
Capital expenditures included in accounts payable and accrued expenses	$ 4.2	$ 1.2