Accounting for Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2018

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Asset Retirement Obligations

A reconciliation of our AROs is as follows:

	Years Ended December 31,
(in millions)	2018			2017
AROs, beginning of period	$	859.3		$	849.9
Liabilities acquired in the Acquisition	258.9			—
Liabilities incurred	27.8			27.1
Liabilities settled	(69.6		)	(64.8		)
Accretion expense	48.0			25.7
Revisions in estimated cash flows	78.2			15.7
Foreign currency translation	(42.5		)	5.7
AROs, end of period	1,160.1			859.3
Less current portion	136.3			98.1
	$	1,023.8		$	761.2