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Discontinued Operations (Details) - USD ($) $ in Millions |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jun. 30, 2021 | Dec. 31, 2021 | Sep. 30, 2021 | Jun. 30, 2021 | Mar. 31, 2021 | Dec. 31, 2020 | Sep. 30, 2020 | Jun. 30, 2020 | Mar. 31, 2020 | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gain on sale of discontinued operations |  |  |  |  |  |  |  |  |  | $ 216.9 | $ 0.0 | $ 0.0
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Income from discontinued operations, net of income taxes |  | $ 19.6 | $ 145.7 | $ 6.9 | $ 5.9 | $ 7.1 | $ 5.6 | $ 5.3 | $ 4.7 | 178.1 | 22.7 | 25.0
Disposal Group, Including Discontinued Operation, Cash Flow Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Cash received from sale of discontinued operations |  |  |  |  |  |  |  |  |  |  | 0.0 | 0.0
Oxford Business | Discontinued Operations, Held-for-sale |  |  |  |  |  |  |  |  |  |  |  |
Disposal Group, Including Discontinued Operation, Assets [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Accounts receivable, net |  |  |  |  |  | 75.9 |  |  |  |  | 75.9 |
Prepaid expenses and income taxes |  |  |  |  |  | 0.8 |  |  |  |  | 0.8 |
Other current assets |  |  |  |  |  | 0.7 |  |  |  |  | 0.7 |
Property and equipment, net |  |  |  |  |  | 14.5 |  |  |  |  | 14.5 |
Operating lease right-of-use assets |  |  |  |  |  | 11.9 |  |  |  |  | 11.9 |
Identifiable intangible assets, net |  |  |  |  |  | 18.0 |  |  |  |  | 18.0 |
Goodwill |  |  |  |  |  | 197.7 |  |  |  |  | 197.7 |
Other non-current assets |  |  |  |  |  | 2.4 |  |  |  |  | 2.4 |
Total assets of discontinued operations |  |  |  |  |  | 321.9 |  |  |  |  | 321.9 |
Accounts payable |  |  |  |  |  | 1.5 |  |  |  |  | 1.5 |
Accrued payroll and contract professional pay |  |  |  |  |  | 27.5 |  |  |  |  | 27.5 |
Operating lease liabilities |  |  |  |  |  | 5.1 |  |  |  |  | 5.1 |
Other current liabilities |  |  |  |  |  | 5.6 |  |  |  |  | 5.6 |
Operating lease liabilities, long-term |  |  |  |  |  | 7.5 |  |  |  |  | 7.5 |
Other long-term liabilities |  |  |  |  |  | 4.0 |  |  |  |  | 4.0 |
Total liabilities of discontinued operations |  |  |  |  |  | $ 51.2 |  |  |  |  | 51.2 |
Oxford Business | Discontinued Operations |  |  |  |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from Sale of Property Held-for-sale | $ 525.0 |  |  |  |  |  |  |  |  |  |  |
Disposal Group, Including Discontinued Operation, Income Statement Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Revenues |  |  |  |  |  |  |  |  |  | 324.3 | 448.5 | 508.3
Costs of services |  |  |  |  |  |  |  |  |  | 223.0 | 306.4 | 349.9
Gross profit |  |  |  |  |  |  |  |  |  | 101.3 | 142.1 | 158.4
Selling, general and administrative expenses |  |  |  |  |  |  |  |  |  | 90.1 | 112.3 | 125.2
Amortization of intangible assets |  |  |  |  |  |  |  |  |  | 0.4 | 0.7 | 0.7
Income before income taxes |  |  |  |  |  |  |  |  |  | 10.8 | 29.1 | 32.5
Provision for income taxes |  |  |  |  |  |  |  |  |  | 1.5 | 6.4 | 7.5
Gain on sale, net of income taxes |  |  |  |  |  |  |  |  |  | 168.8 | 0.0 | 0.0
Income from discontinued operations, net of income taxes |  |  |  |  |  |  |  |  |  | 178.1 | 22.7 | 25.0
Disposal Group, Including Discontinued Operation, Cash Flow Disclosures [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Net cash provided by (used in) operating activities |  |  |  |  |  |  |  |  |  | (84.0) | 49.9 | 40.7
Cash received from sale of discontinued operations |  |  |  |  |  |  |  |  |  | 503.8 | 0.0 | 0.0
Other |  |  |  |  |  |  |  |  |  | (3.9) | (6.4) | (6.3)
Net cash provided by (used in) investing activities |  |  |  |  |  |  |  |  |  | $ 499.9 | $ (6.4) | $ (6.3)

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- Definition Amount of tax expense (benefit) related to a discontinued operation. Includes, but is not limited to, tax expense (benefit) related to income (loss) from operations during the phase-out period, tax expense (benefit) related to gain (loss) on disposal, tax expense (benefit) related to gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and tax expense (benefit) related to adjustments of a prior period gain (loss) on disposal. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=109222160&loc=SL51721525-107759 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 20 -Section 45 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123586238&loc=d3e38679-109324 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109222160&loc=d3e1012-107759 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3A -URI http://asc.fasb.org/extlink&oid=109222160&loc=SL51721523-107759 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I.7) -URI http://asc.fasb.org/extlink&oid=122134291&loc=d3e330036-122817 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5C -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721675-107760 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=121826272&loc=d3e32672-109319 + Details
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