XML 49 R36.htm IDEA: XBRL DOCUMENT v3.21.2
Unsecured Convertible Senior Notes - Interest expense recognized (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
2023 Unsecured Convertible Senior Notes        
Interest Expense, Debt [Abstract]        
Contractual interest expense $ 1,484 $ 3,281 $ 2,969 $ 6,563
Amortization of debt issuance costs 153 209 303 411
Amortization of debt discount   2,417   4,748
Total 1,637 $ 5,907 3,272 $ 11,722
2026 Unsecured Convertible Senior Notes        
Interest Expense, Debt [Abstract]        
Contractual interest expense 2,954   5,907  
Amortization of debt issuance costs 273   519  
Total $ 3,227   $ 6,426