Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities
Net earnings	$ 79,927	$ 85,100
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	5,029	5,371
Noncash operating lease cost	2,600
Amortization of deferred financing costs and debt discount	11,701	8,052
Amortization of premium/discount on marketable securities	(3,189)	(1,825)
Noncash interest expense	4,331	3,096
Noncash royalty revenue	(5,028)	(4,300)
Share-based compensation expense	11,223	8,300
Deferred income tax benefit	(1,689)	(6,233)
Changes in operating assets and liabilities:
Accounts receivable	16,344	(10,687)
Inventories	155	(6,976)
Prepaid expenses and other current assets	(4,236)	(2,778)
Other noncurrent assets	(141)	(342)
Accounts payable	(334)	3,066
Accrued product returns and rebates	(9,013)	17,627
Accrued expenses and other current liabilities	1,120	5,966
Income taxes payable	(7,559)	(7,390)
Other liabilities	(1,903)	90
Net cash provided by operating activities	99,338	96,137
Cash flows from investing activities
Purchases of marketable securities	(361,121)	(491,654)
Sales and maturities of marketable securities	184,467	45,271
Purchases of property and equipment	(707)	(748)
Deferred legal fees	(1)	(679)
Net cash used in investing activities	(177,362)	(447,810)
Cash flows from financing activities
Proceeds from issuance of convertible notes	0	402,500
Convertible notes issuance financing costs	0	(10,435)
Proceeds from issuance of warrants	0	65,688
Purchases of convertible note hedges	0	(92,897)
Proceeds from issuance of common stock	2,665	10,331
Net cash provided by financing activities	2,665	375,187
Net change in cash and cash equivalents	(75,359)	23,514
Cash and cash equivalents at beginning of year	192,248	100,304
Cash and cash equivalents at end of period	116,889	123,818
Supplemental cash flow information
Cash paid for interest on convertible notes	2,516	0
Income taxes paid	35,933	29,930
Noncash investing and financing activities
Deferred legal fees and fixed assets included in accounts payable and accrued expenses	495	280
Property and equipment acquired under build-to-suit lease transaction	0	2,304
Interest capitalized during construction period for build-to-suit lease transaction	0	44
Facility lease financing obligation	$ 0	$ 2,347