Stockholders' Equity - Dividends (Details) - $ / shares				3 Months Ended			9 Months Ended
	Jul. 29, 2019	Apr. 30, 2019	Feb. 19, 2019	Sep. 30, 2019	Sep. 30, 2018		Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Dividends declared per common share outstanding (in dollars per share)	$ 0.29	$ 0.28	$ 0.27	$ 0.29	$ 0.25	[1]	$ 0.84	$ 0.70	[1],[2]

[1] Net revenues and cost of materials and other for the three and nine months ended September 30, 2018 reflect a correction of an intercompany elimination which resulted in an increase in those accounts of $273.7 million and $347.1 million, respectively, not previously reflected on the unaudited consolidated financial statements in our September 30, 2018 Quarterly Report on Form 10-Q filed on November 9, 2018. Such amounts are not considered material to the financial statements and had no impact to operating income or net income for those periods. See Note 23 to our annual audited consolidated financial statements included in Part II, Item 8 of our 2018 Annual Report on Form 10-K, as amended and filed on June 27, 2019, for further discussion.

[2] Income tax expense for the nine months ended September 30, 2018 reflects a correction made in our 2018 Annual Report on Form 10-K (as originally filed on March 1, 2019) to record additional deferred tax expense totaling $5.5 million related to the recognition of a valuation allowance on deferred tax assets recognized in connection with the Big Spring Logistic Assets Acquisition (see Note 5) not previously reported in our September 30, 2018 Quarterly Report on Form 10-Q filed on November 09, 2018. Such amount is not considered material to the financial statements or the trend of earnings for that period. See Note 23 to our annual audited consolidated financial statements included in Part II, Item 8 of our 2018 Annual Report on Form 10-K, as amended and filed on June 27, 2019, for further discussion.