XML 41 R17.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Other Intangible Assets Other Intangible Assets | 12 Months Ended
--- | ---
Dec. 31, 2017
Other Intangible Assets Disclosure [Abstract] |
Other Intangible Assets | Other Intangible Assets Our identifiable intangible assets are as follows (in thousands):
|  | Useful |  |  |  | Accumulated |  |
As of December 31, 2017 |  | Life |  | Gross |  | Amortization |  | Net
Intangible assets subject to amortization: |  |  |  |  |  |  |  |
Supply contract |  | 11.5 |  | $ | 12,227 |  |  | $ | (12,138 | ) |  | $ | 89 |
Intangible assets not subject to amortization: |  |  |  |  |  |  |  |
Rights-of-way assets |  | Indefinite |  | 15,828 |  |  |  |  | 15,828 |
Total |  |  |  | $ | 28,055 |  |  | $ | (12,138 | ) |  | $ | 15,917 |
|  | Useful |  |  |  | Accumulated |  |
As of December 31, 2016 |  | Life |  | Gross |  | Amortization |  | Net
Intangible assets subject to amortization: |  |  |  |  |  |  |  |
Supply contract |  | 11.5 |  | $ | 12,227 |  |  | $ | (11,075 | ) |  | $ | 1,152 |
Intangible assets not subject to amortization: |  |  |  |  |  |  |  |
Rights-of-way assets |  | Indefinite |  | 13,268 |  |  |  |  | 13,268 |
Total |  |  |  | $ | 25,495 |  |  | $ | (11,075 | ) |  | $ | 14,420 |
Amortization of intangible assets was $1.1 million during each of the years ended December 31, 2017, 2016 and 2015, and is included in depreciation and amortization on the accompanying consolidated statements of income and comprehensive income. Amortization expense is estimated to be $0.1 million for the year ended December 31, 2018, at which point our supply contract will be fully amortized.

X
- Definition Other Intangible Assets Disclosure [Abstract] + References No definition available. + Details
Name: | dk_OtherIntangibleAssetsDisclosureAbstract
Namespace Prefix: | dk_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for all or part of the information related to intangible assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -URI http://asc.fasb.org/topic&trid=2144416 + Details
Name: | us-gaap_IntangibleAssetsDisclosureTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration