XML 106 R79.htm IDEA: XBRL DOCUMENT v3.10.0.1

Equity Method Investments Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) joint_venture	Dec. 31, 2017 USD ($)
Schedule of Equity Method Investments [Line Items]
Number of joint ventures | joint_venture	2
Equity method investments | $	$ 104,770	$ 106,465
CP LLC
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	50.00%
Rangeland Rio
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	33.00%

X

- Definition

Equity Method Investment, Number Of Joint Ventures

+ References

No definition available.

+ Details

Name:	dk_EquityMethodInvestmentNumberOfJointVentures
Namespace Prefix:	dk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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

X

- Definition

This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=109237563&loc=d3e33749-111570

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 25
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8813-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.12)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_EquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

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

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=dk_CPLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=dk_RangelandRioMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: