Borrowings (Tables)
 3 Months Ended
Mar. 31, 2018
Debt Disclosure [Abstract]  
Schedule of Long-term Debt Instruments
Borrowings (net of debt issuance costs, debt discount, and amortization) consist of the following:
(in millions)
March 31, 2018
 
December 31, 2017
3.25% Convertible Senior Notes
$
143.6

 
$
141.9

Revolving credit facility
50.7

 
50.7

Total
194.3

 
192.6

Less current maturities (1)
—

 
—

Total long-term debt
$
194.3

 
$
192.6


(1) There are no required principal payments due under the 3.25% Convertible Senior Notes or the revolving credit facility until maturities in November 2021 and October 2022, respectively.
Contractual Obligation, Fiscal Year Maturity Schedule
Total debt principal payments over the next five years are as follows:
(in millions)
Q2-Q4 2018
 
2019
 
2020
 
2021
 
2022
Debt principal payments
$
—

 
$
—

 
$
—

 
$
172.5

 
$
50.7
Schedule of Convertible Debt
The Notes consist of the following:
(in millions)
March 31, 2018
 
December 31, 2017
Liability component:
 
 
 
Principal
$
172.5

 
$
172.5

Less debt issuance costs and debt discount, net of amortization
(28.9
)
 
(30.6
)
Total
$
143.6

 
$
141.9

Less current maturities (1)
—

 
—

Long-term portion
$
143.6

 
$
141.9

 
 
 
 
Equity component (2)
$
29.9

 
$
29.9

(1) There are no required principal payments due until maturity in November 2021.
(2) Recorded in the Consolidated Balance Sheets within additional paid-in capital, inclusive of the $1.3 million of issuance costs in equity.
Schedule of Convertible Debt Interest Expense
The following table sets forth total interest expense recognized related to the Notes:
 
Three Months Ended March 31,
(in millions)
2018
 
2017
3.25% coupon
$
1.4

 
$
1.4

Amortization of debt issuance costs
0.2

 
0.2

Amortization of debt discount
1.5

 
1.4

Total
$
3.1

 
$
3.0
Schedule of Revolving Credit Facilities
Revolving credit facility borrowings consist of the following:
(in millions)
March 31, 2018
 
December 31, 2017
$400.0 million revolving credit facility due October 2022
$
50.7

 
$
50.7

Less current maturities (1)
—

 
—

Long-term portion
$
50.7

 
$
50.7


(1) There are no required principal payments due until maturity in October 2022.