Current Estimated Percentage Of Share Units Awarded Ultimately Issued

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- Definition

Percentage Of Share Units Awarded Ultimately Issued

+ Details

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- Definition

This item represents the conversion ratio used in the calculation of a stock split.

+ Details

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- Definition

As of the balance-sheet date, the aggregate unrecognized cost of share-based awards made to employees under share-based compensation plans that have yet to vest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

+ Details

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- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for share-based compensation plans, using a decimal to express in number of years.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

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- Definition

The total recognized tax benefit related to compensation cost for share-based payment arrangements recognized in income during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

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- Definition

The dollar amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section H

+ Details

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- Definition

Description of the period of time over which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, which may be expressed in a variety of ways (for example, in years, month and year).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

+ Details

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- Definition

Share-based compensation cost during the period with respect to the award, which will be recognized in income (as well as the total recognized tax benefit) or capitalized as part of the cost of an asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64, 65

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- Definition

The total fair value of share-based awards for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(2)

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- Definition

The weighted average fair value as of grant dates pertaining to a share-based award plan other than a stock option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(d)

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- 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.

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- Definition

Number of shares issued during the period as a result of any share-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 5

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- Definition

Value of stock issued during the period as a result of any share-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30, 31

-Article 5

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

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Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended
	Aug. 03, 2011	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost attributable to share-based compensation plans		$ 9.4	$ 2.1	$ 13.9	$ 6.2
Market closing price, per share		$ 35.93		$ 35.93
Total income tax benefit recognized for share-based compensation arrangements		3.6	0.8	5.4	2.4
Common stock conversion ratio	2
HEP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost attributable to share-based compensation plans		0.6	0.4	1.6	1.8
Holly Frontier [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Market closing price, per share		$ 35.93		$ 35.93
Common stock conversion ratio				0.4811
Minimum [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock vesting period, years				one
Minimum [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock vesting period, years				one
Percentage of share units awarded that will ultimately be issued, possible range				0.00%
Percentage of share units awarded that will ultimately be issued, current estimate				125.00%
Minimum [Member] \| Legacy Frontier Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of share units awarded that will ultimately be issued, current estimate				0.00%
Maximum [Member] \| Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock vesting period, years				five
Maximum [Member] \| Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock vesting period, years				three
Percentage of share units awarded that will ultimately be issued, possible range				200.00%
Percentage of share units awarded that will ultimately be issued, current estimate				185.00%
Maximum [Member] \| Legacy Frontier Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of share units awarded that will ultimately be issued, current estimate				125.00%
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of restricted stock vested				8.8	4.2
Total unrecognized compensation cost related to non-vested grants		22.8		22.8
Total unrecognized compensation cost, weighted-average period of recognition, years				1.6
Weighted average grant date fair value				$ 17.25
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost related to non-vested grants		15.4		15.4
Total unrecognized compensation cost, weighted-average period of recognition, years				1.4
Common stock issued, shares				237,802
Common stock issued, fair value				$ 4.8
Weighted average grant date fair value				$ 20.90