XML 38 R27.htm IDEA: XBRL DOCUMENT
v3.24.2

Summary of Significant Accounting Policies Significant Accounting Policies (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2024 | Jun. 30, 2023 | Jun. 30, 2024 | Jun. 30, 2023 | Dec. 31, 2023
Accounting Policies [Abstract] |  |  |  |  |
Treasury money market funds, at fair value | $ 124.7 |  | $ 124.7 |  | $ 153.2
Deferred Costs | 14.6 |  | 14.6 |  | $ 15.1
Amortization of Deferred Charges | $ 1.1 | $ 1.5 | $ 2.4 | $ 2.9 |

X
- Definition Investments in treasury money market funds which are part of the company's assets, measured at fair value. + References No definition available. + Details
Name: | pro_TreasuryMoneyMarketFundsAtFairValue
Namespace Prefix: | pro_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition The amount of amortization of deferred charges applied against earnings during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_AmortizationOfDeferredCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying amount of deferred costs. + References No definition available. + Details
Name: | us-gaap_DeferredCostsCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant