Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Assets [Abstract]
Allowance for bad debt	$ 0.3	$ 0.3
Property and equipment accumulated depreciation	1,941.4	1,757.6
Intangible assets accumulated amortization	112.1	54.6
Liabilities [Abstract]
Installment payable, net of discount of $14.2	14.2	0.0
Installment payable, net of discount of $39.3	$ 39.3	$ 0.0
Common unitholders	180,035,410	164,242,160