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Nature of Business and Summary of Significant Accounting Policies (Tables) | 12 Months Ended
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Jun. 30, 2021 | Dec. 31, 2020
Summary of Assets and Liabilities that are Measured at Fair Value on a Recurring Basis | The following table summarizes the financial assets and liabilities of the Company that are measured at fair value on a recurring basis (in millions):
|  | Fair Value Measurements at June 30, 2021 |
|  | Level 1 |  |  | Level 2 |  |  | Level 3 |
Assets |  |  |  |  |  |  |  |  |  |  |  |
Cash, cash equivalents, and restricted cash (Note 11) |  | $ | 102.4 |  |  | $ | — |  |  | $ | — |
Discretionary retirement plan (Note 12) |  |  | 3.4 |  |  |  | 0.8 |  |  |  | — |
Liabilities |  |  |  |  |  |  |  |  |  |  |  |
Discretionary retirement plan (Note 12) |  |  | 3.4 |  |  |  | 0.8 |  |  |  | — |
|  | Fair Value Measurements at June 30, 2020 |
|  | Level 1 |  |  | Level 2 |  |  | Level 3 |
Assets |  |  |  |  |  |  |  |  |  |  |  |
Cash, cash equivalents, and restricted cash (Note 11) |  | $ | 120.0 |  |  | $ | — |  |  | $ | — |
Discretionary retirement plan (Note 12) |  |  | 2.4 |  |  |  | 1.1 |  |  |  | — |
Liabilities |  |  |  |  |  |  |  |  |  |  |  |
Discretionary retirement plan (Note 12) |  |  | 2.4 |  |  |  | 1.1 |  |  |  | — |
GS Acquisition Holdings Corp II [Member] |  |
Summary Of Reconciliation Of The Shares Of Class A Common Stock |  | As of December 31, 2020, the shares of Class A common stock reflected on the balance sheet are reconciled in the following table:
|  | As of December 31, 2020 |
Gross proceeds |  | $ | 750,000,000 |
Less: |  |  |  |
Proceeds allocated to public warrants |  | $ | (19,587,038 | )
Class A shares issuance costs |  | $ | (41,163,224 | )
Plus: |  |  |  |
Accretion of carrying value to redemption value |  | $ | 60,750,262 |
Class A common stock subject to possible redemption |  | $ | 750,000,000 |

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- Definition Schedule of financial assets and liabilities measured at fair value on recurring basis. + References No definition available. + Details
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- Definition Tabular disclosure of changes in the separate accounts comprising stockholders' equity (in addition to retained earnings) and of the changes in the number of shares of equity securities during at least the most recent annual fiscal period and any subsequent interim period presented is required to make the financial statements sufficiently informative if both financial position and results of operations are presented. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=123467817&loc=d3e21463-112644 + Details
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