Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
ASSETS
Allowance for bad debt	$ 0.3	$ 0.1
Property and equipment accumulated depreciation	2,533.0	2,124.1
Intangible assets accumulated amortization	298.7	171.6
Liabilities:
Current installment payable discount	0.5	0.5
Noncurrent installment payable discount	$ 0.0	$ 26.3
Members’ equity:
Common units issued (in shares)	180,600,728	180,049,316
Common units outstanding (in shares)	180,600,728	180,049,316