Share and Unit-based Plans - SARs Roll Forward Activity (Details) - SARs - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Units
Balance at beginning of year (in shares)	0	0	235,439
Exercised (in shares)	0	0	(235,439)
Balance at end of year (in shares)	0	0	0
Weighted Average Exercise Price
Balance at beginning of year (in dollars per share)	$ 0	$ 0	$ 53.83
Vested (in dollars per share)	0	0	53.83
Balance at end of year (in dollars per share)	$ 0	$ 0	$ 0