v2.4.0.8

Fair Value Measurement (Details) (USD $) In Thousands, unless otherwise specified | Jun. 30, 2013 | Dec. 31, 2012
--- | --- | ---
Fair Value, Inputs, Level 3 [Member] | State and municipal bonds [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Total assets | $ 5,000 | $ 7,200
Fair Value, Inputs, Level 3 [Member] | Other asset-backed securities [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Total assets | 4,700 | 4,000
Fair Value, Measurements, Recurring [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Investment in Unconsolidated Subsidiaries | 44,549 | 33,739
Total assets | 3,923,088 | 3,756,093
Fair Value, Measurements, Recurring [Member] | U.S. Treasury obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 213,822 | 205,857
Fair Value, Measurements, Recurring [Member] | U.S. Government-sponsored enterprise obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 56,925 | 56,947
Fair Value, Measurements, Recurring [Member] | State and municipal bonds [Member] |  |
Assets: |  |
Fair value of available for sale securities | 1,253,172 | 1,219,979
Fair Value, Measurements, Recurring [Member] | Corporate debt, multiple observable inputs [Member] |  |
Assets: |  |
Fair value of available for sale securities | 1,535,533 | 1,455,333
Fair Value, Measurements, Recurring [Member] | Private placement senior notes [Member] |  |
Assets: |  |
Fair value of available for sale securities | 205 | 346
Fair Value, Measurements, Recurring [Member] | Other corporate debt, NRSRO ratings available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 10,269 | 13,835
Fair Value, Measurements, Recurring [Member] | Other corporate debt, NRSRO ratings not available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 885 | 1,010
Fair Value, Measurements, Recurring [Member] | Residential mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 272,233 | 289,850
Fair Value, Measurements, Recurring [Member] | Agency commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 44,449 | 59,464
Fair Value, Measurements, Recurring [Member] | Other commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 70,865 | 74,106
Fair Value, Measurements, Recurring [Member] | Other asset-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 76,075 | 71,272
Fair Value, Measurements, Recurring [Member] | Financial [Member] |  |
Assets: |  |
Fair value of trading securities | 80,579 | 70,900
Fair Value, Measurements, Recurring [Member] | Utilities/Energy [Member] |  |
Assets: |  |
Fair value of trading securities | 36,798 | 31,383
Fair Value, Measurements, Recurring [Member] | Consumer oriented [Member] |  |
Assets: |  |
Fair value of trading securities | 63,149 | 51,100
Fair Value, Measurements, Recurring [Member] | Technology [Member] |  |
Assets: |  |
Fair value of trading securities | 17,949 | 11,495
Fair Value, Measurements, Recurring [Member] | Industrial [Member] |  |
Assets: |  |
Fair value of trading securities | 38,241 | 18,200
Fair Value, Measurements, Recurring [Member] | All other [Member] |  |
Assets: |  |
Fair value of trading securities | 20,116 | 19,540
Fair Value, Measurements, Recurring [Member] | Short-term Investments [Member] |  |
Assets: |  |
Short-term investments | 87,274 | 71,737
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Investment in Unconsolidated Subsidiaries | 0 | 0
Total assets | 336,894 | 262,379
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Treasury obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government-sponsored enterprise obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | State and municipal bonds [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate debt, multiple observable inputs [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Private placement senior notes [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other corporate debt, NRSRO ratings available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other corporate debt, NRSRO ratings not available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Residential mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Agency commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other asset-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Financial [Member] |  |
Assets: |  |
Fair value of trading securities | 80,579 | 70,900
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Utilities/Energy [Member] |  |
Assets: |  |
Fair value of trading securities | 36,798 | 31,383
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Consumer oriented [Member] |  |
Assets: |  |
Fair value of trading securities | 63,149 | 51,100
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Technology [Member] |  |
Assets: |  |
Fair value of trading securities | 17,949 | 11,495
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Industrial [Member] |  |
Assets: |  |
Fair value of trading securities | 38,241 | 18,200
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | All other [Member] |  |
Assets: |  |
Fair value of trading securities | 20,116 | 19,540
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member] |  |
Assets: |  |
Short-term investments | 80,062 | 59,761
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Investment in Unconsolidated Subsidiaries | 0 | 0
Total assets | 3,520,582 | 3,433,574
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Treasury obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 213,822 | 205,857
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government-sponsored enterprise obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 56,925 | 56,947
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | State and municipal bonds [Member] |  |
Assets: |  |
Fair value of available for sale securities | 1,248,147 | 1,212,804
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate debt, multiple observable inputs [Member] |  |
Assets: |  |
Fair value of available for sale securities | 1,535,533 | 1,455,333
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Private placement senior notes [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other corporate debt, NRSRO ratings available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other corporate debt, NRSRO ratings not available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Residential mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 272,233 | 289,850
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Agency commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 44,449 | 59,464
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 70,865 | 74,106
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other asset-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 71,396 | 67,237
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Financial [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Utilities/Energy [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Consumer oriented [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Technology [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Industrial [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | All other [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member] |  |
Assets: |  |
Short-term investments | 7,212 | 11,976
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] |  |
Financial instruments carried at fair value, classified as a part of: |  |
Investment in Unconsolidated Subsidiaries | 44,549 | 33,739
Total assets | 65,612 | 60,140
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Treasury obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government-sponsored enterprise obligations [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | State and municipal bonds [Member] |  |
Assets: |  |
Fair value of available for sale securities | 5,025 | 7,175
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate debt, multiple observable inputs [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Private placement senior notes [Member] |  |
Assets: |  |
Fair value of available for sale securities | 205 | 346
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other corporate debt, NRSRO ratings available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 10,269 | 13,835
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other corporate debt, NRSRO ratings not available [Member] |  |
Assets: |  |
Fair value of available for sale securities | 885 | 1,010
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Residential mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Agency commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other commercial mortgage-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other asset-backed securities [Member] |  |
Assets: |  |
Fair value of available for sale securities | 4,679 | 4,035
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Financial [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Utilities/Energy [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Consumer oriented [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Technology [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Industrial [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | All other [Member] |  |
Assets: |  |
Fair value of trading securities | 0 | 0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member] |  |
Assets: |  |
Short-term investments | $ 0 | $ 0

X
- Details
Name: | pra_FinancialInstrumentsCarriedAtFairValueAbstract
Namespace Prefix: | pra_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_AssetsFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 + Details
Name: | us-gaap_AvailableForSaleSecuritiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investments accounted for under the equity method of accounting as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 18 -Paragraph 6 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6903542&loc=d3e32014-111567 + Details
Name: | us-gaap_EquityMethodInvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph a, f, g -Article 7 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e24584-111560 + Details
Name: | us-gaap_InvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Trading Securities which consist of all investments in certain debt and equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 + Details
Name: | us-gaap_TradingSecuritiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant