v2.4.0.6

Short-Term Debt (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2011	Feb. 06, 2011	Mar. 17, 2011 Senior Notes, 3.25% [Member]	Mar. 17, 2011 Senior Notes, 4.70% [Member]
Short-term Debt [Line Items]
Aggregate redemption price of notes	100.00%		100.00%	100.00%
Aggregate redemption price of notes where merger is not consummated			101.00%	101.00%
Aggregate redemption price of notes percentage			102.00%	102.00%
Senior notes aggregate outstanding principal balance			$ 1,000.0	$ 1,500.0
Discount to senior notes			7.6	29.6
Bridge Loan		$ 2,750.0

X

- Definition

Aggregate Redemption Price Of Notes

+ References

No definition available.

+ Details

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Namespace Prefix:	esv_
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Balance Type:	na
Period Type:	instant

X

- Definition

Aggregate Redemption Price Of Notes Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	esv_
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Aggregate Redemption Price Of Notes Where Merger Is Not Consummated

+ References

No definition available.

+ Details

Name:	esv_AggregateRedemptionPriceOfNotesWhereMergerIsNotConsummated
Namespace Prefix:	esv_
Data Type:	us-types:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Discount To Senior Notes

+ References

No definition available.

+ Details

Name:	esv_DiscountToSeniorNotes
Namespace Prefix:	esv_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Short-Term financing which is expected to be paid back relatively quickly, such as by a subsequent longer-term loan. Also called swing loan or bridge financing.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

+ Details

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

X

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

+ Details

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

X

- Details

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