Earnings (Loss) per Share - Antidilutive Securities and Reconciliation of Weighted-Average Common Shares Outstanding (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Income (Loss) Attributable to Parent, Diluted [Abstract]
Net income (loss) attributable to Penn National	$ 198.7	$ (213.9)	$ 289.7	$ (822.5)
Net income applicable to preferred stock	1.0	0.0	1.5	0.0
Net income (loss) applicable to common stock	$ 197.7	$ (213.9)	$ 288.2	$ (822.5)
Weighted-average number of shares outstanding
Weighted - average common shares outstanding (in shares)	156.0	126.8	155.8	121.3
Convertible debt (in shares)	14.1	0.0	14.1	0.0
Weighted-average common shares outstanding - Diluted (in shares)	172.7	126.8	172.8	121.3
Anti-dilutive securities (in shares)	0.2	3.0	0.2	1.9
Stock options
Weighted-average number of shares outstanding
Dilutive stock options and dilutive RSAs (in shares)	2.2	0.0	2.4	0.0
Restricted stock
Weighted-average number of shares outstanding
Dilutive stock options and dilutive RSAs (in shares)	0.4	0.0	0.5	0.0
Restricted stock
Weighted-average number of shares outstanding
Dilutive stock options and dilutive RSAs (in shares)		0.2		0.3
Convertible Preferred Shares
Weighted-average number of shares outstanding
Anti-dilutive securities (in shares)	0.8		0.8