v3.10.0.1
Goodwill and Other Intangible Assets, Net - Other Intangible Assets, Net (Details) - USD ($)
$ in Millions
6 Months Ended 12 Months Ended
Jun. 30, 2018
Dec. 31, 2017
Gross Intangible Assets    
Beginning balance $ 775.4  
Acquisitions   $ 10.5
Adjustments and Other   (9.6)
Ending balance 776.3 775.4
Accumulated Amortization    
Beginning balance (634.3)  
Additions Charged to Expense (30.4)  
Adjustments and Other 3.8  
Ending balance (660.9) (634.3)
Other Intangible Assets, Net 115.4 141.1
Other Noncurrent Assets | Accounting Standards Update 2014-09    
Accumulated Amortization    
Deferred financing costs 5.7  
Customer relationships, franchise and other municipal agreements    
Gross Intangible Assets    
Beginning balance 666.0  
Acquisitions   9.8
Adjustments and Other   (0.1)
Ending balance 675.7 666.0
Accumulated Amortization    
Beginning balance (554.7)  
Additions Charged to Expense (28.2)  
Adjustments and Other 0.0  
Ending balance (582.9) (554.7)
Other Intangible Assets, Net 92.8  
Non-compete agreements    
Gross Intangible Assets    
Beginning balance 35.6  
Acquisitions   0.7
Adjustments and Other   0.0
Ending balance 36.3 35.6
Accumulated Amortization    
Beginning balance (28.5)  
Additions Charged to Expense (1.6)  
Adjustments and Other 0.0  
Ending balance (30.1) (28.5)
Other Intangible Assets, Net 6.2  
Other intangible assets    
Gross Intangible Assets    
Beginning balance 73.8  
Acquisitions   0.0
Adjustments and Other   (9.5)
Ending balance 64.3 73.8
Accumulated Amortization    
Beginning balance (51.1)  
Additions Charged to Expense (0.6)  
Adjustments and Other 3.8  
Ending balance (47.9) $ (51.1)
Other Intangible Assets, Net $ 16.4