OTHER INCOME AND LOSS (Tables)

12 Months Ended

Dec. 31, 2018

Other Income And Expenses [Abstract]

Summary of Other Income and Loss

The following table summarizes other income and loss for the periods indicated:

	For the year ended December 31,
	2018			2017			2016
	(in thousand)
Interest expense	$	(33,709	)	$	(5,801	)	$	(1,892	)
Interest income		6,810			1,809			507
Amortization of investment discount (premium)		8,573			1,401			(80	)
Other (loss) income		(656	)		601			930
Gain from sale of Priority Review Voucher		—			125,000			—
Total other (loss) income	$	(18,982	)	$	123,010		$	(535	)