Long-Term Debt (Narrative) (Details) - USD ($)					9 Months Ended
	Apr. 01, 2020	Dec. 31, 2019	Sep. 13, 2019	Aug. 27, 2019	Sep. 30, 2020	Sep. 30, 2019	Aug. 31, 2019	Apr. 25, 2017
Debt Instrument [Line Items]
Repayments of debt					$ 26,100,000	$ 573,100,000
Dividend restrictions					The credit agreement contains restrictions on certain payments, including dividends, when availability under the credit agreement is less than or equal to the greater of 100000000 and 0.25 of the lesser of the revolving commitments and the borrowing base and our fixed charge coverage ratio is less than 1 to 1.0 (unless availability under the credit agreement is greater than 100000000 and 0.4 of the lesser of the revolving commitments and the borrowing base). As of 44104, our ability to make restricted payments was not limited as our fixed charge coverage ratio was greater than 1 to 1.0, at 1.14..
Fixed charge coverage ratio					1.14
Fixed charge coverage ratio threshold, percentage of aggregate facility commitments and borrowing base					17.50%
Fixed charge coverage ratio threshold, amount of aggregate facility commitments and borrowing base					$ 70,000,000
Secured debt to EBITDA ratio					0.32
Minimum
Debt Instrument [Line Items]
Fixed charge coverage ratio					1.0
Period for fixed charge coverage ratio threshold (in days)					3 days
Dividend restriction threshold as amount of availability					$ 100,000,000
Dividend restriction threshold as a percentage of revolving commitments and borrowing base					25.00%
Dividend restrictions, fixed charge coverage ratio					1.0
Maximum
Debt Instrument [Line Items]
Secured debt to EBITDA ratio					4.5
Dividend restriction threshold as a percentage of revolving commitments and borrowing base with consideration of fixed charge coverage ratio					40.00%
Federal Funds Rate
Debt Instrument [Line Items]
Spread over variable rate (percent)					0.50%
LIBOR
Debt Instrument [Line Items]
Spread over variable rate (percent)					1.00%
Interest period one (in months)					1 month
Interest period two (in months)					2 months
Interest period three (in months)					3 months
Interest period four (in months)					6 months
Cash
Debt Instrument [Line Items]
Percentage of asset available to borrow against					100.00%
Credit Card Receivables
Debt Instrument [Line Items]
Percentage of asset available to borrow against					90.00%
Investment Grade Accounts
Debt Instrument [Line Items]
Percentage of asset available to borrow against					90.00%
Other Accounts
Debt Instrument [Line Items]
Percentage of asset available to borrow against					85.00%
Midstream Refined Products Inventory
Debt Instrument [Line Items]
Percentage of asset available to borrow against					80.00%
Refined Retail Products Inventory
Debt Instrument [Line Items]
Percentage of asset available to borrow against					75.00%
Retail Merchandise Inventory
Debt Instrument [Line Items]
Percentage of asset available to borrow against					70.00%
Percentage of net orderly liquidation value available to borrow against					85.00%
ABL facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							$ 325,000,000
ABL facility | LIBOR | Minimum
Debt Instrument [Line Items]
Spread over variable rate (percent)					1.50%
ABL facility | LIBOR | Maximum
Debt Instrument [Line Items]
Spread over variable rate (percent)					2.00%
ABL facility | Alternate Base Rate | Minimum
Debt Instrument [Line Items]
Spread over variable rate (percent)					0.50%
ABL facility | Alternate Base Rate | Maximum
Debt Instrument [Line Items]
Spread over variable rate (percent)					1.00%
Term facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							250,000,000.0
Proceeds borrowed from credit facility		$ 50,000,000		$ 200,000,000
Term of facility				4 years
Repayments of debt				$ 57,000,000
Asset-based loan facility, portion included in current maturities		$ 250,000,000.0			$ 225,000,000
Quarterly principal payments	$ 12,500,000
Term facility | LIBOR | Minimum
Debt Instrument [Line Items]
Spread over variable rate (percent)					2.50%
Term facility | LIBOR | Maximum
Debt Instrument [Line Items]
Spread over variable rate (percent)					2.75%
Term facility | Alternate Base Rate | Minimum
Debt Instrument [Line Items]
Spread over variable rate (percent)					1.50%
Term facility | Alternate Base Rate | Maximum
Debt Instrument [Line Items]
Spread over variable rate (percent)					1.75%
Uncommitted incremental facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							150,000,000
Letters of credit
Debt Instrument [Line Items]
Line of credit facility, sublimit							$ 100,000,000
Asset Based Loan Facility
Debt Instrument [Line Items]
Remaining loan amount available					$ 197,300,000
5.625% Senior Notes Due 2027 | Senior Notes
Debt Instrument [Line Items]
Senior notes, principal amount								$ 300,000,000
Interest rate					5.625%			5.625%
4.75% senior notes due 2029 | Senior Notes
Debt Instrument [Line Items]
Senior notes, principal amount			$ 500,000,000
Interest rate					4.75%
4.75% senior notes due 2029 | ABL facility | Line of Credit
Debt Instrument [Line Items]
Interest rate			4.75%		4.75%
Term loan due 2023 | Senior Notes
Debt Instrument [Line Items]
Redemption of aggregate principal amount			$ 500,000,000
Asset Based Loan Facility
Debt Instrument [Line Items]
Asset-based loan facility, portion included in current maturities					$ 0