Basis Points Extension Fee On Total Commitment

No definition available.

Name:	dft_BasisPointsExtensionFeeOnTotalCommitment
Namespace Prefix:	dft_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

Consolidated Total Indebtedness To Gross Assets Value Ratio

+ References

No definition available.

+ Details

Name:	dft_ConsolidatedTotalIndebtednessToGrossAssetsValueRatio
Namespace Prefix:	dft_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Extension option on debt maturity years.

+ References

No definition available.

+ Details

Name:	dft_ExtensionOptionOnDebtMaturityYears
Namespace Prefix:	dft_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Facility amount available for Letters of Credit

+ References

No definition available.

+ Details

Name:	dft_FacilityAmountAvailableForLettersOfCredit
Namespace Prefix:	dft_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Fixed charge coverage ratio.

+ References

No definition available.

+ Details

Name:	dft_FixedChargeCoverageRatio
Namespace Prefix:	dft_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Income from unencumbered assets to unsecured debt.

+ References

No definition available.

+ Details

Name:	dft_IncomeFromUnencumberedAssetsToUnsecuredDebt
Namespace Prefix:	dft_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line Of Credit Commitment If Increased.

+ References

No definition available.

+ Details

Name:	dft_LineOfCreditCommitmentIfIncreased
Namespace Prefix:	dft_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of equity offerings and interests in operating partnerships to be added to tangible net worth threshold.

+ References

No definition available.

+ Details

Name:	dft_PercentageOfEquityOfferingsAndInterestsInOperatingPartnershipsToBeAddedToTangibleNetWorthThreshold
Namespace Prefix:	dft_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Tangible net worth amount.

+ References

No definition available.

+ Details

Name:	dft_TangibleNetWorthAmount
Namespace Prefix:	dft_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Unsecured Debt To Unencumbered Assets

+ References

No definition available.

+ Details

Name:	dft_Unsecureddebttounencumberedassets
Namespace Prefix:	dft_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ 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

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 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: 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

+ Details

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

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ 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 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Details

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

4. Debt Unsecured Credit Facility (Details) (USD $)	3 Months Ended
4. Debt Unsecured Credit Facility (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	May 07, 2015
Debt Instrument [Line Items]
Line of credit	$ 150,000,000us-gaap_LineOfCredit	$ 60,000,000us-gaap_LineOfCredit
Unsecured Credit Facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	560,000,000
Debt Instrument, Maturity Date	May 13, 2018
Extension Option On Debt Maturity Years	1
Basis Points Extension Fee On Total Commitment	15
Line Of Credit Commitment If Increased	800,000,000
Facility amount available for Letters of Credit	35,000,000
Letters of Credit Outstanding, Amount	100,000
Line of credit	150,000,000
Unsecured Credit Facility [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Unsecured Debt To Unencumbered Assets	60.00%
Ratio of Total Indebtedness To Gross Assets Value	60.00%
Unsecured Credit Facility [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Income from Unencumbered Assets To Unsecured Debt	12.50%
Fixed Charge Coverage Ratio	1.70
Tangible Net Worth Amount	1,300,000,000
Percentage Of Equity Offerings And Interests In Operating Partnerships To Be Added To Tangible Net Worth Threshold	80.00%
Unsecured Credit Facility [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Line of credit			$ 180,000,000