Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities
Net earnings	$ 21,518	$ 18,340
Adjustments to reconcile net earnings to net cash provided by operating activities:
Share-based compensation expense	3,988	3,287
Depreciation and amortization	1,732	1,679
Amortization of premium/discount on marketable securities	(451)	(1,102)
Amortization of deferred financing costs and debt discount	4,061	3,848
Noncash interest expense	1,366	1,437
Noncash royalty revenue	(1,567)	(1,576)
Noncash operating lease cost	991	879
Deferred income tax benefit	538	279
Changes in operating assets and liabilities:
Accounts receivable	(31,823)	23,013
Inventories	2,210	(859)
Prepaid expenses and other current assets	(454)	(1,799)
Other noncurrent assets	0	(196)
Accounts payable	(7,017)	4,045
Accrued product returns and rebates	11,824	(18,863)
Accrued expenses and other current liabilities	(3,634)	(3,177)
Income taxes payable	6,654	4,856
Other liabilities	(1,020)	(1,098)
Net cash provided by operating activities	8,916	32,993
Cash flows from investing activities
Purchases of marketable securities	(15,382)	(150,167)
Sales and maturities of marketable securities	53,357	47,143
Purchases of property and equipment	(2,537)	(221)
Deferred legal fees	0	(1)
Net cash provided by (used in) investing activities	35,438	(103,246)
Cash flows from financing activities
Proceeds from issuance of common stock	32	783
Net cash provided by financing activities	32	783
Net change in cash and cash equivalents	44,386	(69,470)
Cash and cash equivalents at beginning of year	181,381	192,248
Cash and cash equivalents at end of period	225,767	122,778
Supplemental cash flow information
Cash paid for interest on convertible notes	1,258	1,258
Income taxes paid	324	800
Noncash investing and financing activities
Deferred legal fees and fixed assets included in accounts payable and accrued expenses	708	250
Property and equipment additions from utilization of tenant improvement allowance	$ 0	$ 282