Investments - Summary of Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Investment [Line Items]
Investments	$ 660,778	$ 82,317
Acquisition related expenses	27,900
Unamortized acquisition related expenses	27,700
White Cliffs
Investment [Line Items]
Investments	10,268	9,373
Advantage Joint Venture
Investment [Line Items]
Investments	76,834	72,944
Delaware Crossing JV
Investment [Line Items]
Investments	68,707	0
EPIC Y-Grade
Investment [Line Items]
Investments	165,853	0
EPIC Crude
Investment [Line Items]
Investments	$ 339,116	$ 0

The capitalized costs incurred (excluded from amortization), as of the date of the balance sheet, to purchase, lease or otherwise acquire an unproved property, including costs of lease bonuses and options to purchase or lease properties, the portion of costs applicable to minerals when land including mineral rights is purchased in fee, brokers' fees, recording fees, legal costs, and other costs incurred in acquiring properties.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(c)(7)(ii))
-URI http://asc.fasb.org/extlink&oid=82851474&loc=d3e511914-122862

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