Stock Compensation Plans - Weighted Average Grant Date Fair Values of Stock Options and the Assumptions Used (Parenthetical) (Details) - shares	12 Months Ended
Dec. 31, 2021	Dec. 31, 2019
Black-Scholes model assumptions:
Options granted in period (in shares)	0	0

Gross number of share options (or share units) granted during the period.

No definition available.

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration