Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net income (loss)	$ 35.3	$ (172.9)	$ 51.7
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Impairment	3.6	234.0	0.0
Depreciation and amortization	25.1	29.3	29.3
Non-cash stock-based compensation	6.1	0.5	4.9
Provisions for credit losses on accounts receivable	0.8	6.4	1.1
Deferred income taxes	12.6	(52.5)	4.2
Other	0.2	2.0	0.5
Changes in operating assets and liabilities
Accounts and notes receivable	(29.2)	44.6	(12.7)
Prepaid expenses and other current assets	(5.4)	(2.1)	(6.9)
Accounts payable	20.7	(17.5)	5.2
Accrued liabilities and other	(16.4)	(31.6)	(1.3)
Net cash provided by operating activities	53.4	40.2	76.0
Investing activities
Purchases of leasehold improvements and equipment	(9.6)	(8.4)	(10.2)
Cost of contracts	0.0	(2.6)	(2.6)
Proceeds from sale of other investments and equipment	0.5	1.2	0.3
Noncontrolling interest buyout	0.0	(1.7)	0.0
Net cash used in investing activities	(9.1)	(11.5)	(12.5)
Financing activities
Proceeds from credit facility revolver	371.6	484.1	455.6
Payments on credit facility revolver	(387.2)	(488.4)	(470.6)
Payments on credit facility term loan	(15.5)	(11.3)	(11.3)
Payments of debt issuance costs	(1.3)	(1.7)	0.0
Payments on other long-term borrowings	(7.7)	(5.0)	(2.3)
Distributions to noncontrolling interest	(2.3)	(1.4)	(3.2)
Repurchases of common stock	0.0	(15.3)	(47.6)
Net cash used in financing activities	(42.4)	(39.0)	(79.4)
Effect of exchange rate changes on cash and cash equivalents	(0.1)	0.1	0.1
Increase (decrease) in cash and cash equivalents	1.8	(10.2)	(15.8)
Cash and cash equivalents at beginning of year	13.9	24.1	39.9
Cash and cash equivalents at end of year	15.7	13.9	24.1
Cash paid during the period for
Interest	19.4	18.8	17.9
Income taxes	$ 0.5	$ 2.4	$ 15.3