Description of Business and Presentation of Financials Statements - Impact of Adoption on Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost of products sold	$ 3,595,916	[1]	$ 2,753,459	$ 6,943,041	$ 5,394,634
Operating expenses	296,215	[1]	316,261	616,503	623,987
Selling, general and administrative expenses	68,675		59,803	133,339	117,051
Other, net	$ 1,364		327	$ 2,710	1,397
Restatement Adjustment [Member] | Accounting Standards Update 2017-07
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost of products sold			19		37
Operating expenses			609		1,218
Selling, general and administrative expenses			227		405
Other, net			855		1,660
Scenario, Previously Reported [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Cost of products sold			2,753,440		5,394,597
Operating expenses			315,652		622,769
Selling, general and administrative expenses			59,576		116,646
Other, net			$ (528)		$ (263)

[1] (1) During the three months ended June 30, 2018, we recognized an adjustment in our Lubricants and Specialty Products segment to correct an expense misclassification related to the three months ended March 31, 2018, whereby $24 million of inventory transportation costs were classified as operating expenses, which should have been included in cost of products sold.