Amount of debt hedged by interest rate derivatives.

No definition available.

Name:	prxl_AmountOfDebtHedgedByInterestRateDerivatives
Namespace Prefix:	prxl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Credit facility, maximum borrowing capacity under term loan and revolver combined

+ References

No definition available.

+ Details

Name:	prxl_Creditfacilitymaximumborrowingcapacity
Namespace Prefix:	prxl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The total amount of the contingent obligations allowed to issue under letters of credit as of the reporting date

+ References

No definition available.

+ Details

Name:	prxl_LettersofCreditmaximumissuanceamount
Namespace Prefix:	prxl_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Term Loan, Quarterly Principal Payment Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	prxl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fixed interest rate related to the interest rate derivative.

+ References

No definition available.

+ Details

Name:	us-gaap_DerivativeFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
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-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=prxl_A2014CreditAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=prxl_LIBORPlusMarginMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=prxl_OneMonthLIBORPlusRateMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_VariableRateAxis=prxl_OneMonthLIBORPlusMarginMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=prxl_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=prxl_SwinglineLoanMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_RevolvingCreditFacilityMember
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Period Type:

- Details

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- Details

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Period Type:

- Details

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- Details

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- Details

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- Details

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Credit Agreements 2014 Credit Agreement (Details) - USD ($)	1 Months Ended	3 Months Ended	9 Months Ended
	May 31, 2013	Sep. 30, 2016	Mar. 31, 2015	Jun. 30, 2016	Mar. 11, 2016	Oct. 01, 2015	Oct. 15, 2014	Sep. 30, 2011
Debt Instrument [Line Items]
Derivative, Fixed Interest Rate	0.73%					1.104%
2014 Credit Agreement [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity							$ 500,000,000
Debt Instrument, Face Amount					$ 0.005
2014 Credit Agreement [Member] \| LIBOR Plus Margin [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		50.00%	1.75%
2014 Credit Agreement [Member] \| One Month LIBOR Plus Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.00%
2014 Credit Agreement [Member] \| One Month LIBOR Plus Margin [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate			0.75%
2014 Credit Agreement [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt							200,000,000
Debt Instrument, Face Amount					0.003
2014 Credit Agreement [Member] \| Swingline Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity							100,000,000
2014 Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity							300,000,000
Letters of Credit, maximum issuance amount							10,000,000
2016 Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt				$ 25,000,000
Credit facility, maximum borrowing capacity							$ 750,000,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.25%
2016 Credit Agreement [Member] \| LIBOR Plus Margin [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		2.00%
2016 Credit Agreement [Member] \| One Month LIBOR Plus Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		1.00%
2016 Credit Agreement [Member] \| One Month LIBOR Plus Margin [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate		100.00%
2016 Credit Agreement [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Long-term Debt				$ 395,000,000	$ 0
2016 Credit Agreement [Member] \| Term Loan [Member] \| Debt Instrument, Redemption, Period One [Member]
Debt Instrument [Line Items]
Term Loan, Quarterly Principal Payment Percentage					0.63%
2016 Credit Agreement [Member] \| Term Loan [Member] \| Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Term Loan, Quarterly Principal Payment Percentage					1.25%
2016 Credit Agreement [Member] \| Term Loan [Member] \| Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Term Loan, Quarterly Principal Payment Percentage					1.88%
2016 Credit Agreement [Member] \| Term Loan [Member] \| Debt Instrument, Redemption, Period Four [Member]
Debt Instrument [Line Items]
Term Loan, Quarterly Principal Payment Percentage					2.50%
2016 Credit Agreement [Member] \| Swingline Loan [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity					$ 0
2016 Credit Agreement [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Line of Credit					0
Line of Credit Facility, Current Borrowing Capacity					0
Letters of Credit, maximum issuance amount					$ 10,000,000
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Amount Of Debt Hedged By Interest Rate Derivatives	$ 100,000,000	$ 100,000,000
Derivative, Fixed Interest Rate								1.30%