Commitments and contingencies (Tables)

6 Months Ended

Jun. 30, 2020

Commitments and Contingencies Disclosure [Abstract]

Changes in Total Environmental Liabilities

Changes in total environmental liabilities are as follows:

(in millions)
Environmental liabilities at December 31, 2019	$	78.7
Revised obligation estimates	11.7
Environmental payments	(7.4)
Environmental liabilities at June 30, 2020	$	83.0

Schedule of Environmental Liabilities

(in millions)	Balance Sheet Classification	June 30, 2020		December 31, 2019
Current environmental liabilities	Other accrued expenses	$	26.6	$	25.0
Long-term environmental liabilities	Other long-term liabilities	$	56.4	$	53.7