Income and Other Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Deferred compensation plans	$ 13.3	$ 34.1
Deferred income	6.3	14.3
Allowance for uncollectible receivables	1.2	1.3
Deferred liabilities	3.7	1.9
Net operating losses and credit carryforward	9.4	11.7
Deferred tax assets	33.9	63.3
Valuation allowance	(0.5)	(1.1)
Net deferred tax asset	33.4	62.2
Deferred tax liabilities:
Intangible assets in excess of tax basis	135.0	143.0
Property and equipment in excess of tax basis	35.3	31.2
Other	16.2	15.9
Deferred tax liabilities	186.5	190.1
Net deferred tax liability	$ (153.1)	$ (127.9)