Name:	pcln_ConvertibleDebtConversionDisclosuresAbstract
Namespace Prefix:	pcln
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

The price per share of the conversion feature embedded in the debt instrument. (2011 Draft Taxonomy)

+ Details

Name:	pcln_DebtInstrumentConvertibleConversionPrice2010
Namespace Prefix:	pcln
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the strike price per share of purchasable shares in accordance with the terms of convertible debt hedge agreement. If the market value per share of the entity's common stock at maturity is above the strike price, the entity is entitled to receive from the counterparties net shares of the entity's common stock over the strike price of the hedge (but not to exceed the counterparties strike price).

+ Details

Name:	pcln_DebtInstrumentHedgeAgreementStrikePricePurchasableShares
Namespace Prefix:	pcln
Data Type:	us-types:perShareItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	pcln_NetIncomePerShareDisclosureAbstract
Namespace Prefix:	pcln
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) in the future that were not included in the computation of diluted EPS because to do so would increase EPS amounts or decrease loss per share amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 13, 14

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph c

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
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.

+ Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest rate stated in the contractual debt agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt securities outstanding shall be assumed to have been converted at the beginning of the period (or at time of issuance, if later), and the resulting common shares shall be included in common shares used to calculate diluted earnings per shares. The dilutive effect of convertible debt securities shall be reflected in diluted Earnings Per Share by application of the if-converted method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 26, 27, 28

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate awards of share options and nonvested shares to be issued to an employee under a share-based compensation arrangement are considered options for purposes of computing diluted earnings per share. Such share-based awards shall be considered to be outstanding as of the grant date for purposes of computing diluted earnings per share even though their exercise may be contingent upon vesting. Those share-based awards are included in the diluted Earnings Per Share (EPS) computation even if the employee may not receive (or be able to sell) the stock until some future date. Accordingly, all shares to be issued shall be included in computing diluted EPS if the effect is dilutive. The dilutive effect of share-based compensation arrangements shall be computed using the treasury stock method. If the equity share options or other equity instruments are outstanding for only part of a period, the shares issuable shall be weighted to reflect the portion of the period during which the equity instruments were outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 20

+ Details

Name:	us-gaap_IncrementalCommonSharesAttributableToShareBasedPaymentArrangements
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 8

+ Details

Name:	us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph a

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 8

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesOutstandingBasic
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

NET INCOME PER SHARE (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011 Outstanding Stock Awards	Jun. 30, 2010 Outstanding Stock Awards	Jun. 30, 2011 Outstanding Stock Awards	Jun. 30, 2010 Outstanding Stock Awards	Jun. 30, 2011 Convertible Debt.	Jun. 30, 2011 Convertible Debt.	Jun. 30, 2011 0.75% Convertible Senior Notes due September 2013	Dec. 31, 2006 0.75% Convertible Senior Notes due September 2013
NET INCOME PER SHARE
Weighted average number of basic common shares outstanding (in shares)	49,718	47,791	49,519	47,054
Weighted average dilutive stock options, restricted stock, restricted stock units and performance share units (in shares)	614	1,394	911	1,554
Assumed conversion of convertible debt (in shares)	773	1,662	704	2,424
Weighted average number of diluted common and common equivalent shares outstanding (in shares)	51,105	50,847	51,134	51,032
Anti-dilutive Securities Excluded from Computation of Earnings Per Share
Anti-dilutive potential common shares (in shares)					1,649	2,921	1,461	2,815	1,100	1,200
Convertible Spread Hedges
Conversion price of Company's Convertible Senior Notes due September 30, 2013 (in dollars per share)											$ 40.38	$ 40.38
Strike price of shares purchasable by counterparties under hedge agreement (in dollars per share)											$ 50.47	$ 50.47
Interest rate on Convertible Senior Notes (as a percent)											0.75%	0.75%