Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share [Abstract]
Net income attributable to HollyFrontier stockholders	$ 342,466	$ 272,014	$ 956,064	$ 284,313
Participating securities’ (restricted stock) share in earnings	1,171	1,735	3,321	1,822
Net income (loss) attributable to common shares	$ 341,295	$ 270,279	$ 952,743	$ 282,491
Average number of shares of common stock outstanding	175,097	176,149	175,865	176,143
Effect of dilutive variable restricted shares and performance share units	1,830	381	1,692	473
Average number of shares of common stock outstanding assuming dilution	176,927	176,530	177,557	176,616
Basic earnings (loss) per share	$ 1.95	$ 1.53	$ 5.42	$ 1.60
Diluted earnings (loss) per share	$ 1.93	$ 1.53	$ 5.37	$ 1.60
Excludes anti-dilutive restricted and performance share units of:	0	104	2	120