Payments To Acquire Interest In Joint Venture, Non-Cash Assets

No definition available.

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Balance Type:	debit
Period Type:	duration

- Definition

Variable Interest Entity, Number Of Shares Acquired

+ References

No definition available.

+ Details

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Data Type:	xbrli:sharesItemType
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- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Balance Type:	debit
Period Type:	instant

- Definition

The number of countries in which the entity operates as of balance sheet date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The cash outflow associated with the investment in or advances to an entity in which the reporting entity shares control of the entity with another party or group.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of income (loss) from operations derived by the reporting entity during the period from the Variable Interest Entity (VIE).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph d
-URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5747-111685

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- 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

Name:	us-gaap_VariableInterestEntityLineItems
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Balance Type:	na
Period Type:	duration

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=SL6759159-111685

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=prsp_HavasHealthInc.Member
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- Details

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- Details

Name:	dei_LegalEntityAxis=prsp_VencoreHoldingCorp.andKGSHoldingCorp.Member
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- Details

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Significant Accounting Policies - Variable Interest Entities (Details) $ in Millions		3 Months Ended
	Feb. 17, 2017 USD ($) country shares	Mar. 31, 2017 USD ($)	Mar. 30, 2018 USD ($)	Dec. 31, 2017 USD ($)
Havas Health, Inc.
Variable Interest Entity [Line Items]
Number of countries in which entity operates \| country	50
Ownership percentage in VIE	50.00%
Havas Health, Inc. \| Not Primary Beneficiary
Variable Interest Entity [Line Items]
Ownership percentage in VIE	50.00%
Vencore Holding Corp. and KGS Holding Corp.
Variable Interest Entity [Line Items]
Equity method investments			$ 1.9	$ 2.2
Vencore Holding Corp. and KGS Holding Corp. \| Not Primary Beneficiary
Variable Interest Entity [Line Items]
Payments to acquire interest in joint venture	$ 0.5
Contribution of property	$ 3.0
Number of shares acquired \| shares	1,000,000
Gain recognized in VIE		$ 3.0
HVH Precision Analytics LLC \| Havas Health, Inc. \| Not Primary Beneficiary
Variable Interest Entity [Line Items]
Payments to acquire interest in joint venture	$ 3.5
Ownership percentage in VIE	50.00%