XML 85 R45.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Investments - Amortized Cost, Gross Unrealized Gains and Losses, Fair Values of Investments (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Debt and Equity Securities |  |
Amortized Cost | $ 195 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 195 |
Available-for-Sale Securities |  |
Amortized Cost |  | $ 38
Gross Unrealized Gains |  | 0
Gross Unrealized Losses |  | 0
Fair Value |  | 38
Asset-backed securities |  |
Debt Securities |  |
Amortized Cost | 33 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 33 |
Corporate bonds |  |
Debt Securities |  |
Amortized Cost | 99 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 99 |
U.S. government agencies and government- sponsored agencies |  |
Debt Securities |  |
Amortized Cost | 7 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 7 |
U.S. treasuries |  |
Debt Securities |  |
Amortized Cost | 46 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 46 |
Available-for-Sale Securities |  |
Amortized Cost |  | 37
Gross Unrealized Gains |  | 0
Gross Unrealized Losses |  | 0
Fair Value |  | 37
Exchange traded fund |  |
Equity Securities |  |
Amortized Cost | 1 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | 1 |
Available-for-Sale Securities |  |
Amortized Cost |  | 1
Gross Unrealized Gains |  | 0
Gross Unrealized Losses |  | 0
Fair Value |  | $ 1
Other debt securities |  |
Debt Securities |  |
Amortized Cost | 9 |
Gross Unrealized Gains | 0 |
Gross Unrealized Losses | 0 |
Fair Value | $ 9 |

X
- Definition Available-For-Sale Debt And Equity Securities [Abstract] + References No definition available. + Details
Name: | tnet_AvailableForSaleDebtAndEquitySecuritiesAbstract
Namespace Prefix: | tnet_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Securities, Available-For-Sale, And Equity Securities, FV-NI + References No definition available. + Details
Name: | tnet_DebtSecuritiesAvailableForSaleAndEquitySecuritiesFVNI
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Debt Securities, Available-For-Sale, And Equity Securities, FV-NI [Abstract] + References No definition available. + Details
Name: | tnet_DebtSecuritiesAvailableForSaleAndEquitySecuritiesFVNIAbstract
Namespace Prefix: | tnet_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Securities, Available-For-Sale, And Equity Securities, FV-NI, Cost + References No definition available. + Details
Name: | tnet_DebtSecuritiesAvailableForSaleAndEquitySecuritiesFVNICost
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Debt Securities, Available-For-Sale, And Equity Securities, FV-NI, Gross Unrealized Gains + References No definition available. + Details
Name: | tnet_DebtSecuritiesAvailableForSaleAndEquitySecuritiesFVNIGrossUnrealizedGain
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt Securities, Available-For-Sale, And Equity Securities, FV-NI, Gross Unrealized Loss + References No definition available. + Details
Name: | tnet_DebtSecuritiesAvailableForSaleAndEquitySecuritiesFVNIGrossUnrealizedLoss
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Equity Securities, FV-NI [Abstract] + References No definition available. + Details
Name: | tnet_EquitySecuritiesFVNIAbstract
Namespace Prefix: | tnet_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity Securities, FV-NI, Accumulated Gross Unrealized Gain, Before Tax + References No definition available. + Details
Name: | tnet_EquitySecuritiesFVNIAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Equity Securities, FV-NI, Accumulated Gross Unrealized Loss, Before Tax + References No definition available. + Details
Name: | tnet_EquitySecuritiesFVNIAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | tnet_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on 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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost 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 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedGainBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAccumulatedGrossUnrealizedLossBeforeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesAmortizedCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- 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 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: 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=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740 + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cost of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). Excludes equity method investment and investment in equity security without readily determinable fair value. + References No definition available. + Details
Name: | us-gaap_EquitySecuritiesFvNiCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ExchangeTradedFundsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |