Capital Stock - Changes in Outstanding Common Stock (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Changes in Common Stock [Roll Forward]
Outstanding, beginning of year (in shares)	107,588	106,697	106,363
Shares issued for exercise of options (in shares)	0	0	281
Shares issued for time vested restricted stock (net of forfeitures) (in shares)	1,368	740	53
Shares issued for employee stock purchase plan (in shares)	375	151	0
Outstanding, end of year (in shares)	109,331	107,588	106,697