Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Condensed Consolidated Statements of Cash Flows (Unaudited) [Abstract]
Cash Flows Provided by Operating Activities from Continuing Operations	$ 20.7	$ 26.1
Cash Flows from Investing Activities from Continuing Operations:
Capital expenditures	(17.5)	(27.9)
Proceeds from disposal of property and other assets	0.5	0.9
Deposits into Capital Construction Fund	(2.2)	(2.2)
Withdrawals from Capital Construction Fund	2.2	2.2
Contribution from A&B	26.7	16.3
Net cash provided by (used in) investing activities from continuing operations	9.7	(10.7)
Cash Flows from Financing Activities from Continuing Operations:
Proceeds from issuance of debt, net of issuance costs	185.1	115.8
Payments of debt	(5.7)	(109.7)
Proceeds from (payments on) line-of-credit agreements, net	(6.0)
Distribution upon Separation	151.4
Proceeds from issuance of capital stock	21.7	9.0
Distribution to A&B for proceeds from issuance of capital stock	(21.7)
Cash assumed by A&B upon separation	(2.5)
Dividends paid	(26.7)	(26.6)
Net cash used in financing activities from continuing operations	(7.2)	(11.5)
Cash Flows from Discontinued Operations:
Cash flows used in operating activities of discontinued operations	(24.3)	(8.5)
Cash flows used in investing activities of discontinued operations	(18.8)	(5.6)
Cash flows from financing activities of discontinued operations	33.9	11.2
Net cash flows used in discontinued operations	(9.2)	(2.9)
Net Increase in Cash and Cash Equivalents	14.0	1.0
Cash and cash equivalents, beginning of period	21.5	14.0
Cash and cash equivalents, end of period	35.5	15.0
Other Cash Flow Information:
Interest paid	4.3	3.9
Income taxes paid	14.1	0.2
Other Non-cash Information:
Depreciation and amortization expense	37.2	36.5
Accrued dividend	6.4	13.1
Capital expenditures included in accounts payable and accrued liabilities	$ 1.7	$ 5.4