Description of Business: (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Other comprehensive income (loss)	$ 1.0	$ 0.8	$ 1.6	$ 1.4
Comprehensive Income	18.2	19.9	48.0	31.7
Amortization of prior service cost included in net periodic pension cost		(0.5)		(1.0)
Amortization of net loss included in net periodic pension cost		1.3		3.5
Net loss and prior service cost			(0.8)	(1.1)
Previously reported
Other comprehensive income (loss)		(2.0)		(1.4)
Comprehensive Income		17.1		28.9
Amortization of prior service cost included in net periodic pension cost		0.7		1.0
Amortization of net loss included in net periodic pension cost		(2.7)		(3.5)
Net loss and prior service cost				$ 1.1