Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 309,052	$ 170,345
Short-term investments, available for sale	102,349	148,697
Accounts receivable, net of allowances of $32.3 and $32.2 million, respectively	241,841	244,416
Inventories	134,348	125,813
Income taxes receivable	4,926	4,565
Assets held for sale	2,800	4,200
Other current assets	44,623	41,799
Total current assets	839,939	739,835
Property and equipment, net	77,613	98,762
Restricted cash equivalents	39,809	32,531
Goodwill	390,109	403,278
Intangible assets, net	74,722	123,008
Deferred tax assets	39,449	45,083
Other assets	37,393	15,504
Total assets	1,499,034	1,458,001
Current liabilities:
Accounts payable	148,587	123,935
Accrued and other liabilities	79,323	98,090
Deferred revenue	60,547	55,833
Convertible senior notes, net – current	334,274	0
Income taxes payable	5,077	5,309
Total current liabilities	627,808	283,167
Convertible senior notes, net	118,688	318,957
Imputed financing obligation related to build-to-suit lease	0	13,944
Noncurrent contingent and other liabilities	7,179	28,801
Deferred tax liabilities	3,770	11,652
Noncurrent income taxes payable	15,481	20,169
Total liabilities	772,926	676,690
Commitments and contingencies (Note 13)
Stockholders' equity:
Preferred stock, $0.01 par value; 5,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.01 par value; 150,000 shares authorized; 55,347 and 54,249 shares issued, respectively	553	542
Additional paid-in capital	821,205	745,661
Treasury stock, at cost; 12,927 and 9,070 shares, respectively	(489,083)	(375,574)
Accumulated other comprehensive gain (loss)	(12,814)	8,138
Retained earnings	406,247	402,544
Total stockholders’ equity	726,108	781,311
Total liabilities and stockholders’ equity	$ 1,499,034	$ 1,458,001