Annual report pursuant to Section 13 and 15(d)

LONG-TERM DEBT (2.5% Convertible Senior Notes Due 2023) (Details)

v3.20.4
LONG-TERM DEBT (2.5% Convertible Senior Notes Due 2023) (Details) - 2.5% Convertible Senior Notes Due 2023
$ / shares in Units, shares in Millions
12 Months Ended
Dec. 31, 2020
USD ($)
$ / shares
shares
Debt Instrument [Line Items]  
Face amount $ 550,000,000
Interest rate, stated percentage 2.50%
Conversion ratio 0.0147005
Conversion premium 54.40%
Last reported sale price used to calculate conversion premium | $ / shares $ 44.05
Maximum number of shares issuable upon conversion | shares 8.1
Carrying amount of equity component $ 64,000,000.0
Unamortized debt discount balance $ 29,100,000
Debt discount amortization period 2 years
Value of convertible notes, if fully settled in shares, exceeded the principal amount $ 44,100,000
Effective interest rate 5.70%
Redemption, Defined Changes of Control [Member]  
Debt Instrument [Line Items]  
Redemption price, percentage 100.00%