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Concentration of Credit Risk - Additional Information (Detail) - Credit Concentration Risk [Member] $ in Millions | Dec. 31, 2021 USD ($)
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Corporate Bonds [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | $ 159.5
Mortgage Backed Securities [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | 82.6
U.S. Treasuries [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | 67.3
U.S. Government Agency Securities [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | 42.0
Asset Backed Securities [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | 29.6
Money Market Funds [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | 13.9
Mutual Funds [Member] |
Concentration Risk [Line Items] |
Fair value of financial instruments | $ 6.3

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- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(6)) -URI http://asc.fasb.org/extlink&oid=120398452&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=124260329&loc=d3e26610-111562 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=123581744&loc=d3e27161-111563 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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