| Balance Sheet Details | 
Balance Sheet Details Cash, cash equivalents, restricted cash and investments consist of the following: 
|  |  
|  |  |  |  |  |  |  |  |  
|   | September 30, 2017 |   | December 31, 2016 |  
|   | (in thousands) |  
| Cash and cash equivalents | $ | 71,576 | 
 |   | $ | 81,086 | 
 |  
| Short-term restricted cash | 615 | 
 |   | 614 | 
 |  
| Long-term restricted cash | 1,905 | 
 |   | 1,196 | 
 |  
| Total cash, cash equivalents and restricted cash | 74,096 | 
 |   | 82,896 | 
 |  
| Short-term investments | — | 
 |   | 47,918 | 
 |  
| Long-term investments | — | 
 |   | 5,991 | 
 |  
|   | $ | 74,096 | 
 |   | $ | 136,805 | 
 | 
 Inventory consists of the following: 
|  |  
|  |  |  |  |  |  |  |  |  
|   | September 30, 2017 |   | December 31, 2016 |  
|   | (in thousands) |  
| Work-in-process | $ | 27,093 | 
 |   | $ | 13,947 | 
 |  
| Finished goods | 36,599 | 
 |   | 12,636 | 
 |  
|   | $ | 63,692 | 
 |   | $ | 26,583 | 
 | 
 Property and equipment, net consists of the following: 
|  |  
|  |  |  |  |  |  |  |  |  |  |  
|   | Useful Life(in Years)
 |   | September 30, 2017 |   | December 31, 2016 |  
|   |   |   | (in thousands) |  
| Furniture and fixtures | 5 |   | $ | 2,108 | 
 |   | $ | 1,983 | 
 |  
| Machinery and equipment | 3-5 |   | 32,495 | 
 |   | 27,028 | 
 |  
| Masks and production equipment | 2 |   | 10,625 | 
 |   | 9,153 | 
 |  
| Software | 3 |   | 5,085 | 
 |   | 3,625 | 
 |  
| Leasehold improvements | 1-5 |   | 13,965 | 
 |   | 11,635 | 
 |  
| Construction in progress | N/A |   | 228 | 
 |   | 39 | 
 |  
|   |   |   | 64,506 | 
 |   | 53,463 | 
 |  
| Less accumulated depreciation and amortization |   |   | (41,170 | ) |   | (32,914 | ) |  
|   |   |   | $ | 23,336 | 
 |   | $ | 20,549 | 
 | 
 
 
Depreciation expense for the three and nine months ended September 30, 2017 was $3.4 million and $9.2 million, respectively. Depreciation expense for the three and nine months ended September 30, 2016 was $3.0 million and $8.3 million, respectively.
 Deferred revenue and deferred profit consist of the following: 
|  |  
|  |  |  |  |  |  |  |  |  
|   | September 30, 2017 |   | December 31, 2016 |  
|   | (in thousands) |  
| Deferred revenue—rebates | $ | 130 | 
 |   | $ | 464 | 
 |  
| Deferred revenue—distributor transactions | 22,902 | 
 |   | 7,987 | 
 |  
| Deferred cost of net revenue—distributor transactions | (5,808 | ) |   | (2,460 | ) |  
|   | $ | 17,224 | 
 |   | $ | 5,991 | 
 | 
 
 Accrued price protection liability consists of the following activity: 
|  |  
|  |  |  |  |  |  |  |  |  
|   | Nine Months Ended September 30, |  
|   | 2017 |   | 2016 |  
|   | (in thousands) |  
| Beginning balance | $ | 15,176 | 
 |   | $ | 20,026 | 
 |  
| Charged as a reduction of revenue | 36,256 | 
 |   | 34,501 | 
 |  
| Reversal of unclaimed rebates | (70 | ) |   | (1,302 | ) |  
| Payments | (23,133 | ) |   | (36,113 | ) |  
| Ending balance | $ | 28,229 | 
 |   | $ | 17,112 | 
 | 
 Accrued expenses and other current liabilities consist of the following: 
|  |  
|  |  |  |  |  |  |  |  |  
|   | September 30, 2017 |   | December 31, 2016 |  
|   | (in thousands) |  
| Accrued technology license payments | $ | 5,186 | 
 |   | $ | 5,850 | 
 |  
| Accrued professional fees | 1,079 | 
 |   | 1,620 | 
 |  
| Accrued engineering and production costs | 1,565 | 
 |   | 1,232 | 
 |  
| Accrued restructuring | 4,195 | 
 |   | 536 | 
 |  
| Accrued royalty | 1,164 | 
 |   | 846 | 
 |  
| Accrued leases - other | 1,418 | 
 |   | 1,560 | 
 |  
| Accrued customer credits | 1,159 | 
 |   | 1,207 | 
 |  
| Income tax liability | 4,167 | 
 |   | 235 | 
 |  
| Other | 7,090 | 
 |   | 3,272 | 
 |  
|   | $ | 27,023 | 
 |   | $ | 16,358 | 
 |  |