Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 77.9	$ 86.1
Short-term marketable securities, available-for-sale	28.6	29.1
Accounts Receivable, Net, Current	67.3	74.1
Inventory	46.1	35.2
Prepaid and other current assets	7.5	6.8
Total current assets	227.4	231.3
Property and equipment, net	65.9	54.7
Intangible assets, net	2.0	2.2
Goodwill	3.7	3.7
Other assets	0.4	0.1
Total assets	299.4	292.0
Current liabilities:
Accounts payable and accrued liabilities	45.1	38.9
Accrued payroll and related expenses	16.7	24.9
Current portion of long-term debt	1.7	2.3
Current portion of deferred revenue	0.6	0.8
Total current liabilities	64.1	66.9
Other liabilities	4.1	3.9
Total liabilities	$ 68.2	$ 70.8
Commitments and contingencies (Note 4)
Stockholders' equity:
Preferred stock, $0.001 par value, 5.0 shares authorized; no shares issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 0.0	$ 0.0
Common stock, $0.001 par value, 100.0 authorized; 83.7 and 83.4 issued and outstanding, respectively, at March 31, 2016; and 82.0 and 81.7 shares issued and outstanding, respectively, at December 31, 2015	0.1	0.1
Additional paid-in capital	806.0	776.8
Accumulated other comprehensive loss	(0.3)	(0.3)
Accumulated deficit	(574.6)	(555.4)
Total stockholders’ equity	231.2	221.2
Total liabilities and stockholders’ equity	$ 299.4	$ 292.0