Stock-Based Compensation Status of Outstanding Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statusof Stock Options [Abstract]
Outstanding as of January 1, 2019	90,615
Granted	0	0	0
Exercised	(69,852)
Outstanding as of December 31, 2019	20,763	90,615
Outstanding as of January 1, 2019	$ 77.16
Exercised	76.96
Outstanding as of December 31, 2019	$ 77.82	$ 77.16