Capital Stock - Basic and Diluted Per-share Computations (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Equity [Abstract]
Issued and outstanding, beginning of period	58,921	61,176
Weighted average number of shares issued (repurchased), net	91	(758)
Weighted average number of shares outstanding - basic	59,012	60,418
Weighted average number of shares outstanding - diluted	59,012	60,418