Business Segments - Geographic Information on Certain Long-Lived Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 2,829,053	$ 1,791,401	[1]	$ 1,443,988	[1]
Certain Long-Lived Assets	9,969,700	8,432,100		6,827,700
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	2,370,400	1,300,300		958,300
Certain Long-Lived Assets	8,003,900	6,634,300		5,050,500
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	447,100	468,900		485,700
Certain Long-Lived Assets	1,761,200	1,644,600		1,635,900
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	11,600	22,200		0
Certain Long-Lived Assets	204,600	153,200		141,300
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 2,829,100	$ 1,791,400		$ 1,444,000

[1] ¹ Reclassified to conform with current presentation (see Notes C and E). 2017 revenue is presented net of $58.9 million of transportation, gathering and processing costs as historically shown prior to the adoption of ASC 606 on January 1, 2018. See Notes to Consolidated Financial Statements, page 58.