4.	Balance Sheet Components

Cash and Cash Equivalents

Cash and cash equivalents consisted of the following (in thousands):

	June 30, 2017		December 31, 2016
Cash	$	205,018	$	79,239
Money market funds		85,259		94,543
Total cash and cash equivalents	$	290,277	$	173,782

At June 30, 2017 and December 31, 2016, a total of $22.6 million and $24.3 million, respectively, of our cash and cash equivalents were held outside of the U.S. in our foreign subsidiaries to be used primarily for our China operations.

Investments

All investments are classified as available-for-sale. The amortized cost, gross unrealized holding gains or losses, and fair value of the Company’s available-for-sale investments by major investments type are summarized in the tables below (in thousands):

	June 30, 2017
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
Corporate bonds	$	86,266	$	67	$	(28	)	$	86,305
Certificate of deposits		1,036		—		—			1,036
Bond and mutual funds		20,053		744		—			20,797
Equity investments		126		61		—			187
Total investments	$	107,481	$	872	$	(28	)	$	108,325

	December 31, 2016
	Amortized Cost		Gross Unrealized Holding Gains		Gross Unrealized Holding Losses			Fair Value
Corporate bonds	$	126,550	$	182	$	(49	)	$	126,683
Certificate of deposits		1,037		—		—			1,037
Bond and mutual funds		22,305		157		—			22,462
Equity investments		125		100		—			225
Total investments	$	150,017	$	439	$	(49	)	$	150,407

At June 30, 2017, all of the available-for-sale investments had contractual maturities within two years. The Company periodically reviews its available-for-sale investments for other-than-temporary impairment. The Company considers factors such as the duration, severity and the reason for the decline in value, the potential recovery period and our intent to sell. For debt securities, the Company also considers whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis, and (ii) the amortized cost basis cannot be recovered as a result of credit losses. During the three and six months ended June 30, 2017 and 2016, the Company did not recognize any other-than-temporary impairment loss.

Accrued Liabilities

Accrued liabilities consisted of the following (in thousands):

	June 30, 2017		December 31, 2016
Preclinical and clinical trial accruals	$	28,795	$	29,550
Payroll and related accruals		10,673		14,232
Professional services		1,653		1,252
Other		7,413		5,880
Total accrued liabilities	$	48,534	$	50,914