Debt (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

Schedule of Convertible Senior Notes

The 2025 Notes consist of the following components as of December 31, 2018 (in thousands):

	December 31, 2018
Liability component:
Principal	$	1,150,000
Less: debt discount and issuance costs, net of amortization	(275,920		)
Net carrying amount	$	874,080
Equity component:	$	285,225

The 2019 Notes consist of the following components as of December 31, 2018 and 2017 (in thousands):

	December 31, 2018			December 31, 2017
Liability component:
Principal	$	690,000		$	690,000
Less: debt discount and issuance costs, net of amortization	(3,448		)	(27,087		)
Net carrying amount	$	686,552		$	662,913
Equity component:	$	101,276		$	101,276

Schedule of Interest Expense

The following table sets forth total interest expense included in the consolidated statements of income for the years ended December 31, 2018, 2017 and 2016 (in thousands):

	2018			2017			2016
Amortization of debt discount and issuance costs	$	46,493		$	22,826		$	22,040
Coupon interest payable on 2025 Notes	874			—			—
Revolving credit facility contractual interest expense	368			—			—
Capitalization of interest expense	(4,533		)	(3,987		)	(3,402		)
Total interest expense	$	43,202		$	18,839		$	18,638