Consolidated and Combined Statements of Operations - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
Revenues		$ 1,736.9	$ 1,460.4	$ 1,462.4
Operating costs:
Cost of revenues		1,404.5	1,188.4	1,167.7
Selling, general, and administrative expenses		179.5	153.9	163.0
Impairment charge		0.0	23.2	0.0
Total operating costs		1,584.0	1,365.5	1,330.7
Total operating profit		152.9	94.9	131.7
Interest expense		6.8	0.9	0.0
Other, net (income) expense		(0.7)	(1.0)	1.6
Total other (income) expense		6.1	(0.1)	1.6
Income before income taxes		146.8	95.0	130.1
Provision (benefit) for income taxes:
Current		16.2	(3.1)	30.1
Deferred		17.3	22.4	10.3
Total provision for income taxes		33.5	19.3	40.4
Net income		$ 113.3	$ 75.7	$ 89.7
Net income per common share:
Basic (in dollars per share)		$ 2.34	$ 1.55	$ 1.84
Diluted (in dollars per share)		$ 2.32	$ 1.54	$ 1.84
Weighted average number of shares outstanding(1):
Basic (in shares)	[1]	47.9	48.8	48.8
Diluted (in shares)	[1]	48.4	48.9	48.8
Dividends declared per common share (in dollars per share)		$ 0.20	$ 0.05	$ 0

[1] For periods prior to the Separation, the denominator for basic and diluted net income per common share was calculated using the 48.8 million shares of common stock outstanding immediately following the Separation.