Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities
Net earnings	$ 51,067	$ 57,089
Adjustments to reconcile net earnings to net cash provided by operating activities:
Realized loss on sales of securities	(93)	0
Depreciation and amortization	3,355	3,487
Amortization of operating lease assets	1,230
Amortization of deferred financing costs and debt discount	7,748	4,307
Amortization of premium/discount on marketable securities	(1,625)	(1,835)
Non-cash interest expense	2,851	1,905
Non-cash royalty revenue	(3,368)	(2,780)
Share-based compensation expense	7,309	5,703
Deferred income tax (benefit) provision	861	(395)
Changes in operating assets and liabilities:
Accounts receivable	18,439	(7,776)
Inventories	(365)	(4,376)
Prepaid expenses and other current assets	(3,581)	(8,060)
Other non-current assets	(140)	(342)
Accounts payable	886	(3,838)
Accrued product returns and rebates	(11,129)	1,701
Accrued expenses and other current liabilities	(1,307)	2,964
Income taxes payable	(9,703)	(15,938)
Other non-current liabilities	(755)	1,873
Net cash provided by operating activities	61,680	33,689
Cash flows from investing activities
Purchases of marketable securities	(264,926)	(491,655)
Sales and maturities of marketable securities	96,165	19,466
Purchases of property and equipment	(245)	(557)
Deferred legal fees	(1)	(401)
Net cash used in investing activities	(169,007)	(473,147)
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	2,423	9,503
Net cash provided by financing activities	2,423	374,359
Net change in cash and cash equivalents	(104,904)	(65,099)
Cash and cash equivalents at beginning of year	192,248	100,304
Cash and cash equivalents at end of period	87,344	35,205
Supplemental cash flow information
Cash paid for interest on convertible notes	1,258	0
Income taxes paid	24,795	29,279
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	2,704	2,707
Non-cash investing and financing activities
Deferred legal fees included in accounts payable and accrued expenses	280	$ 480
Lease assets and tenant receivable obtained for new operating leases	$ 31,727