Share and Unit-based Plans - SARs Roll Forward Activity (Details) - SARs - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Units
Balance at beginning of year (shares)	0	235,439	284,146
Granted (shares)	0	0	0
Exercised (shares)	0	(235,439)	(48,707)
Balance at end of year (shares)	0	0	235,439
Weighted Average Exercise Price (in dollars per share)
Balance at beginning of year (in dollars per share)	$ 0	$ 53.83	$ 53.85
Granted (in dollars per share)	0	0
Vested (in dollars per share)	0	53.83	53.95
Balance at end of year (in dollars per share)	$ 0	$ 0	$ 53.83