Income Tax Matters, Textuals (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended		3 Months Ended
	Jun. 30, 2014	Sep. 30, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2013 Canada Revenue Agency Competent Authority [Member]
Income Tax Contingency [Line Items]
Income tax provision	$ 14.5		$ 11.7	$ 23.9	$ 19.9
Effective tax rate	37.00%		38.60%	37.20%	27.70%
Unrecognized tax benefits, increase (decrease) including interest and penalties					(7.2)
Increase (decrease) in unrecognized tax benefits, including interest and penalties			0.3
Increase (decrease) in effective tax rate due to unrecognized tax benefits, including interest and penalties			0.90%		(10.00%)
Decrease in cash tax benefit from settlement of tax audit						7.7
Refund adjustment from settlement	7.2			7.2
Cash tax benefit expected to be refunded in next 12 months		2.8
Gross unrecognized tax benefits	3.8			3.8
Gross unrecognized tax benefits that would impact effective tax rate	2.7			2.7
Reduction in gross unrecognized tax benefits	$ 1.8			$ 1.8