Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions		Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Receivables, allowance for expected losses	[1]	$ 17.1	$ 12.7
Preferred stock, par value		$ 0.01	$ 0.01
Preferred stock, authorized		1,000,000.0	1,000,000.0
Preferred stock, Issued		0	0
Common stock, par value		$ 0.01	$ 0.01
Common stock, Authorized		65,000,000.0	65,000,000.0
Common stock, Issued		36,900,000	35,900,000
Common stock, Outstanding		28,900,000	33,000,000.0
Treasury stock, Shares		8,000,000.0	2,900,000

[1] As of December 31, 2022, the CECL reserve balance is comprised of a $16.5 million provision for accounts receivable and a $0.6 million provision for unbilled receivables and contract assets. As of December 31, 2021, the CECL reserve balance is comprised of a $12.0 million provision for accounts receivable and a $0.7 million provision for unbilled receivables and contract assets. As of December 31, 2020, the CECL reserve balance was comprised of a $10.1 million provision for accounts receivable and a $0.4 million provision for unbilled receivables and contract assets.