Stock-Based Compensation Plans (Information Regarding Stock Options) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value	$ 2,000,000.0
Shares
Outstanding — beginning of year (in shares)	114,943	114,943	0
Granted (in shares)	0	0	114,943
Exercised (in shares)	0	0	0
Canceled (in shares)	0	0	0
Outstanding — end of year (in shares)	114,943	114,943	114,943
Exercisable — end of year (in shares)	0	0	0
Weighted Average Exercise Price
Outstanding — beginning of year (in dollars per share)	$ 48.63	$ 48.63	$ 0
Granted (in dollars per share)	0	0	48.63
Exercised (in dollars per share)	0	0	0
Canceled (in dollars per share)	0	0	0
Outstanding — end of year (in dollars per share)	48.63	48.63	48.63
Exercisable — end of year (in dollars per share)	$ 0	$ 0	$ 0
Weighted Average Remaining Contractual Life	7 years 3 months 18 days	8 years 3 months 18 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
General vesting period (years)	3 years
General expiration period, from date of grant or time of termination (years)	10 years
Recognition of unearned compensation, (years)	3 years
Unearned compensation cost	$ 300,000
Number of stock options vested	$ 0	$ 0	$ 0