Earnings per Share - Narrative (Details) - shares	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Nov. 19, 2013
Long-Term Debt
Potentially dilutive shares (in shares)	390,000	133,000	288,000
Antidilutive shares excluded from computation of diluted earnings per share (in shares)	52,000	220,000
Convertible Notes
Long-Term Debt
Interest rate	1.00%	1.00%		1.00%

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of contingently issuable shares. Contingently issuable shares are those shares that are issuable for little or no cash contingent on certain conditions being met.

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+ Details