Exit and Disposal Costs Exit and Disposal Costs (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended	18 Months Ended
	Oct. 26, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2015	Jun. 30, 2017
Restructuring Cost and Reserve [Line Items]
Business Exit Costs		$ 2.9
Scenario, Forecast [Member]
Restructuring Cost and Reserve [Line Items]
Business Exit Costs					$ 8.0
Office Space Leases [Member]
Restructuring Cost and Reserve [Line Items]
Contractual Obligation		6.5
Subsequent Event [Member] | Office Space Leases [Member]
Restructuring Cost and Reserve [Line Items]
Gain (Loss) on Contract Termination	$ (3.2)
Mid Continent Divestiture 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Business Exit Costs			$ 1.0	$ 9.5
Mid Continent Divestiture 2015 [Member] | Office Space Leases [Member]
Restructuring Cost and Reserve [Line Items]
Contractual Obligation		$ 3.8