Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
ASSETS
Allowance for bad debt	$ 0.3	$ 0.3
Property and equipment, accumulated depreciation	2,745.8	2,533.0
Intangible assets, accumulated amortization	360.4	298.7
Liabilities:
Current installment payable discount	$ 0.0	$ 0.5
Members’ equity:
Common units issued (in shares)	181,051,875	180,600,728
Common units outstanding (in shares)	181,051,875	180,600,728