Earnings Per Share - Potentially Dilutive Shares Excluded From Diluted EPS Calculation (Details) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Convertible Senior Notes Maturing May 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	2,519	8,997	2,519	8,997
Convertible Senior Notes Maturing September 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	3,168	13,202	3,168	13,202
Convertible Senior Notes Maturing February 2026
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	28,676		28,676