Stock-Based Compensation - Long-Term Awards (Details) shares in Thousands	Mar. 31, 2021 shares
Total target performance awards as of December 31, 2020	320
2018 Program [Member] | Long-Term Awards [Member]
Total target performance awards as of December 31, 2020	82	[1]
2019 Program [Member] | Long-Term Awards [Member]
Total target performance awards as of December 31, 2020	70	[1]
2020 Program [Member] | Annual Awards [Member]
Total target performance awards as of December 31, 2020	92
2020 Program [Member] | Long-Term Awards [Member]
Total target performance awards as of December 31, 2020	76

[1] 2019 Long-Term Awards