XML 83 R68.htm IDEA: XBRL DOCUMENT v3.19.2
Debt - Schedule of Interest Expense (Details) - Senior Notes - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
2022 Notes        
Debt Instrument [Line Items]        
Contractual interest coupon $ 11.8 $ 11.8 $ 23.6 $ 23.6
Amortization of debt issuance costs 0.6 0.6 1.2 1.2
Total 12.4 12.4 24.8 24.8
5.50% convertible senior notes due 2021        
Debt Instrument [Line Items]        
Contractual interest coupon 2.9 3.0 5.9 5.9
Amortization of debt discount 1.8 1.6 3.5 3.2
Amortization of debt issuance costs 0.3 0.3 0.6 0.6
Total $ 5.0 $ 4.9 $ 10.0 $ 9.7