Earnings Per Share - Potentially Dilutive Shares Excluded From Dilutive EPS Calculation (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Convertible Senior Notes Maturing May 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	8,997	8,997	8,997
Convertible Senior Notes Maturing September 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	13,202	10,344	0
Convertible Senior Notes Maturing March 2032
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	0	524	2,403