Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 324,371	$ 75,105
Short-term investments	500	6,862
Accounts and notes receivable, net of allowance of $1,559 and $754 as of September 30, 2018 and December 31, 2017, respectively	116,518	56,064
Contract assets, net	13,263	0
Inventory	39,221	45,465
Prepaid expenses and other current assets	30,514	21,696
Total current assets	524,387	205,192
Property and equipment, net of accumulated depreciation of $38,599 and $36,477 as of September 30, 2018 and December 31, 2017, respectively	35,613	31,172
Deferred income tax assets, net	18,080	15,755
Intangible assets, net	16,956	18,823
Goodwill	25,043	14,927
Long-term notes receivable, net of current portion	38,220	36,877
Other assets	23,396	15,366
Total assets	681,695	338,112
Current liabilities:
Accounts payable	8,998	8,592
Accrued liabilities	36,908	23,502
Contract with customer, liability, current	89,637	70,401
Current portion of business acquisition contingent consideration	1,736	1,693
Other current liabilities	115	89
Total current liabilities	141,505	107,950
Deferred revenue, net of current portion	69,382	54,881
Liability for unrecognized tax benefits	1,805	1,706
Long-term deferred compensation	3,590	3,859
Business acquisition contingent consideration, net of current portion	0	1,048
Other long-term liabilities	5,751	1,224
Total liabilities	222,033	170,668
Commitments and contingencies (Note 11)
Stockholders’ equity:
Preferred stock, $0.00001 par value; 25,000,000 shares authorized; no shares issued and outstanding as of September 30, 2018 and December 31, 2017	0	0
Common stock, $0.00001 par value; 200,000,000 shares authorized; 58,419,742 and 52,969,869 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	1	1
Additional paid-in capital	447,933	201,672
Treasury stock at cost, 20,220,227 shares as of September 30, 2018 and December 31, 2017	(155,947)	(155,947)
Retained earnings	169,301	123,185
Accumulated other comprehensive loss	(1,626)	(1,467)
Total stockholders’ equity	459,662	167,444
Total liabilities and stockholders’ equity	681,695	338,112
Current portion of deferred revenue
Current liabilities:
Contract with customer, liability, current	89,637	70,401
Customer deposits
Current liabilities:
Contract with customer, liability, current	$ 4,111	$ 3,673

The aggregate of amounts due from customers or clients, within one year of the balance sheet date (or one operating cycle, if longer), for goods or services that have been delivered or sold in the normal course of business and an amount representing an agreement for an unconditional promise by the maker to pay the entity (holder) a definite sum of money at a future date within one year of the balance sheet, reduced to their estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection and net of any write-downs taken for collection uncertainty on the part of the holder, respectively.

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- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).