XML 69 R57.htm IDEA: XBRL DOCUMENT
v3.25.3

Commitments, Contingencies, and Other Matters (Details) - USD ($) |  |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 01, 2023 | Sep. 15, 2022 | May 10, 2022 | Sep. 30, 2025 | Jun. 30, 2025 | Oct. 31, 2024 | Sep. 30, 2025 | Jun. 30, 2025 | Sep. 30, 2024 | Mar. 31, 2024 | Sep. 30, 2025 | Sep. 30, 2024 | Aug. 31, 2025 | May 31, 2025
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase obligation |  |  |  |  |  | $ 220,000,000 |  |  |  |  |  |  |  |
Purchase commitment, period |  |  |  |  |  | 5 years |  |  |  |  |  |  |  |
Purchase obligation, year one |  |  |  |  |  | $ 44,000,000 |  |  |  |  |  |  |  |
Purchase obligation, year two |  |  |  |  |  | 44,000,000 |  |  |  |  |  |  |  |
Purchase obligation, year three |  |  |  |  |  | 44,000,000 |  |  |  |  |  |  |  |
Purchase obligation, year four |  |  |  |  |  | 44,000,000 |  |  |  |  |  |  |  |
Purchase obligation, year five |  |  |  |  |  | $ 44,000,000 |  |  |  |  |  |  |  |
Payments for purchase obligation |  |  |  |  |  |  | $ 14,300,000 |  | $ 10,800,000 |  | $ 37,600,000 | $ 31,800,000 |  |
Authorized to repurchase |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,000,000.0 | $ 10,000,000.0
Number of shares repurchased (in shares) |  |  |  | 300,000 | 300,000 |  |  |  |  |  |  |  |  |
Average share price (in usd per share) |  |  |  | $ 30.60 | $ 31.91 |  |  |  |  |  |  |  |  |
Repurchase of common stock |  |  |  | $ 10,000,000.0 | $ 10,000,000 |  | $ 10,000,000 | $ 10,000,000 |  | $ 50,019,000 |  |  |  |
Common stock, shares outstanding (in shares) |  |  |  | 73,800,000 |  |  | 73,800,000 |  |  |  | 73,800,000 |  |  |
Treasury stock, shares (in shares) |  |  |  | 639,751 |  |  | 639,751 |  |  |  | 639,751 |  |  |
Pegasystems Litigation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
JPI cost | $ 57,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |
JPI, threshold amount | $ 500,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |
Appeal process, period |  |  |  | 4 years |  |  | 4 years |  |  |  | 4 years |  |  |
JPI expense |  |  |  |  |  |  | $ 3,200,000 |  | $ 3,600,000 |  | $ 9,400,000 | $ 12,600,000 |  |
JPI current |  |  |  | $ 12,500,000 |  |  | 12,500,000 |  |  |  | 12,500,000 |  |  |
JPI noncurrent |  |  |  | $ 13,600,000 |  |  | $ 13,600,000 |  |  |  | $ 13,600,000 |  |  |
Pegasystems Litigation | Misappropriation of Trade Secrets |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount awarded in settlement |  |  | $ 2,036,000,000.000 |  |  |  |  |  |  |  |  |  |  |
Pegasystems Litigation | Violation of Virginia Computer Crimes Act |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount awarded in settlement |  |  | $ 1 |  |  |  |  |  |  |  |  |  |  |
Pegasystems Litigation | Attorney's Fees Associated |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount awarded in settlement |  | $ 23,600,000 |  |  |  |  |  |  |  |  |  |  |  |
Pegasystems Litigation | Statutory Post Judgement Interest on Judgmental |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount awarded in settlement |  | $ 122,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Interest on damages awarded (as a percentage) |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |
Youyong Zou Litigation |  |  |  |  |  |  |  |  |  |  |  |  |  |
Loss Contingencies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount awarded in settlement |  | $ 5,000,000 |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Gain Contingency, Damages Awarded, Interest, Percentage + References No definition available. + Details
Name: | appn_GainContingencyDamagesAwardedInterestPercentage
Namespace Prefix: | appn_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Judgment Preservation Insurance, Threshold Amount + References No definition available. + Details
Name: | appn_JudgmentPreservationInsuranceThresholdAmount
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Litigation, Appeal Process, Period + References No definition available. + Details
Name: | appn_LitigationAppealProcessPeriod
Namespace Prefix: | appn_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | instant

X
- Definition Litigation, Judgment Preservation Insurance, Cost + References No definition available. + Details
Name: | appn_LitigationJudgmentPreservationInsuranceCost
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Litigation, Judgment Preservation Insurance, Current + References No definition available. + Details
Name: | appn_LitigationJudgmentPreservationInsuranceCurrent
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Litigation, Judgment Preservation Insurance Expense + References No definition available. + Details
Name: | appn_LitigationJudgmentPreservationInsuranceExpense
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Litigation, Judgment Preservation Insurance, Noncurrent + References No definition available. + Details
Name: | appn_LitigationJudgmentPreservationInsuranceNoncurrent
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Payments For Purchase Obligation + References No definition available. + Details
Name: | appn_PaymentsForPurchaseObligation
Namespace Prefix: | appn_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount authorized for purchase of share under share repurchase plan. Includes, but is not limited to, repurchase of stock and unit of ownership. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 505 -SubTopic 30 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481520/505-30-50-4 + Details
Name: | srt_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix: | srt_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.6-05(4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-2 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(4)(b)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479170/946-210-S99-1 Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.6-09(7)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479134/946-220-S99-3 + Details
Name: | us-gaap_CommonStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount awarded from other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedFromOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Period covered by the long-term purchase commitment, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_LongtermPurchaseCommitmentPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- 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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 275 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482861/275-10-50-9 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-9 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 720 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483359/720-20-50-1 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 27 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482395/460-10-55-27 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-9 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 4 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-4 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482425/460-10-50-3 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 450 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483076/450-20-50-1 + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum amount of purchase arrangement in which the entity has agreed to expend funds to procure goods or services from a supplier. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in fifth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligationDueInFifthYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in fourth fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligationDueInFourthYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in second fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligationDueInSecondYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of purchase arrangement to be paid in third fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 942 -SubTopic 235 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477314/942-235-S99-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S50 -Paragraph 4 -Publisher FASB -URI https://asc.fasb.org/1943274/2147480738/235-10-S50-4 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(a)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480678/235-10-S99-3 + Details
Name: | us-gaap_PurchaseObligationDueInThirdYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Total cost of shares repurchased divided by the total number of shares repurchased. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481549/505-30-45-1 + Details
Name: | us-gaap_TreasuryStockAcquiredAverageCostPerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of previously issued common shares repurchased by the issuing entity and held in treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481549/505-30-45-1 + Details
Name: | us-gaap_TreasuryStockCommonShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares that have been repurchased during the period and are being held in treasury. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 + Details
Name: | us-gaap_TreasuryStockSharesAcquired
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 10 -Topic 505 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481112/505-10-50-2 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480008/505-10-S99-1 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 505 -SubTopic 30 -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481549/505-30-45-1 + Details
Name: | us-gaap_TreasuryStockValueAcquiredCostMethod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_LitigationCaseAxis=appn_PegasystemsLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GainContingenciesByNatureAxis=appn_MisappropriationOfTradeSecretsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GainContingenciesByNatureAxis=appn_ViolationOfVirginiaComputerCrimesActMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GainContingenciesByNatureAxis=appn_AttorneysFeesAssociatedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GainContingenciesByNatureAxis=appn_StatutoryPostJudgementInterestOnJudgmentalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_LitigationCaseAxis=appn_YouyongZouLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |