CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
OPERATING ACTIVITIES:
Net income	$ 8,811	$ 62,492
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58,826	53,985
Non-cash impairment charges	0	5,764
Deferred income tax benefit	(401)	(9,077)
Share-based compensation	8,922	9,859
Amortization of debt issuance costs and expenses associated with debt refinancing	5,551	2,713
Non-cash lease expense	1,760	1,430
Accretion of bond issuance discount	6,780	0
Loss on disposal of property and equipment	517	611
Change in fair value of contingent consideration and others	(708)	10
Changes in assets and liabilities:
Accounts receivable	95,293	(30,356)
Inventories	(47,041)	(21,558)
Prepaid expenses and other current assets	2,191	(14,806)
Other non-current assets	6,149	2,846
Accounts payable, accrued expenses and other current liabilities	(88,671)	16,410
Contract liabilities	(637)	(1,971)
Other non-current liabilities	(3,411)	(344)
Net cash provided by operating activities	53,931	78,008
INVESTING ACTIVITIES:
Purchases of property and equipment	(23,736)	(33,750)
Acquired in-process research and development milestone	(5,000)	0
Proceeds from note receivable	0	495
Proceeds from sale of property and equipment	3,302	35
Net cash used in investing activities	(25,434)	(33,220)
FINANCING ACTIVITIES:
Proceeds from borrowings of long-term indebtedness	127,700	101,200
Payments on debt	(388,500)	(105,000)
Purchase of option hedge on convertible notes	(104,248)	0
Proceeds from convertible notes issuance	575,000	0
Proceeds from sale of stock purchase warrants	44,563	0
Payment of debt issuance costs	(20,264)	0
Purchases of treasury stock	(100,000)	0
Proceeds from exercised stock options	3,598	2,213
Cash taxes paid in net equity settlement	(4,397)	(6,212)
Net cash provided by (used in) financing activities	133,452	(7,799)
Effect of exchange rate changes on cash and cash equivalents	121	257
Net increase in cash and cash equivalents	162,070	37,246
Cash and cash equivalents at beginning of period	198,911	138,838
Cash and cash equivalents at end of period	$ 360,981	$ 176,084