Convertible Notes (Tables)

12 Months Ended

Dec. 31, 2017

Convertible Notes

Schedule of components of convertible notes

The components of the convertible notes were as follows (in thousands):

				Carrying Amount
	Interest Rates			December 31,
Debt	December 31, 2017		Maturities	2017		2016
0.375% Convertible Senior Notes due 2018	0.375	%	2018	$	7,393	$	340,916
1.25% Convertible Senior Notes due 2020	1.25	%	2020		16,608		310,565
					24,001		651,481
Less current portion					7,393		—
				$	16,608	$	651,481

Schedule of annual maturities of convertible notes

Annual maturities of all convertible notes are as follows (in millions):

2018	$	7.7
2019		—
2020		19.1
2021		—
Thereafter		—
	$	26.8

Schedule of carrying amount and fair value of convertible notes

The carrying amount and fair value of our convertible notes were as follows (in thousands):

	December 31,
	2017				2016
	Carrying				Carrying
	Amount		Fair Value		Amount		Fair Value
0.375% Convertible Senior Notes due 2018	$	7,393	$	14,129	$	340,916	$	749,988
1.25% Convertible Senior Notes due 2020		16,608		35,431		310,565		761,300
	$	24,001	$	49,560	$	651,481	$	1,511,288