Cost of Contracts, net (Tables)

12 Months Ended

Dec. 31, 2020

Revenue From Contract With Customer [Abstract]

Schedule of Contract Cost

Cost of contracts, net, as of December 31, 2020 and 2019 was as follows:

	December 31,
(millions)	2020			2019
Cost of contracts	$	26.0		$	26.0
Accumulated amortization		(21.2	)		(21.7	)
Cost of contracts, net	$	4.8		$	4.3

Schedule of Amortization Expense Related to Cost of Contracts

The table below shows the Company's amortization expense related to costs of contracts for the years ended December 31, 2020, 2019 and 2018, which was primarily included in Depreciation and amortization within the Consolidated Statements of (Loss) Income.

	Year Ended December 31,
(millions)	2020		2019		2018
Amortization expense	$	1.6	$	1.9	$	3.0
Weighted average life (years)		7.8		10.0		9.4