Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Schedule of Cash as Reported in Condensed Consolidated Statements of Cash Flows

Cash as reported in the condensed consolidated statements of cash flows includes the aggregate amounts of cash and cash equivalents and the restricted cash, and consists of following (in thousands):

	March 31, 2018		December 31, 2017		March 31, 2017		December 31, 2016
Cash and cash equivalents	$	168,414	$	181,568	$	135,669	$	188,480
Restricted cash (SRX Cardio)		47		173		174		178
Total cash balance in condensed consolidated    statements of cash flows	$	168,461	$	181,741	$	135,843	$	188,658

Percentage of Revenue from Significant Collaboration Customers

Collaboration customers who accounted for 10% or more of total revenues were as follows:

	Three Months Ended March 31,
	2018	2017
Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.	47%	16%
Daiichi Sankyo, Inc.	27%	43%
Bristol-Myers Squibb Company and Pfizer Inc.	17%	34%

Comparison of Reported Condensed Consolidated Balance Sheet, Statement of Operations Under New Guidance

the following adjustments were made to the condensed consolidated balance sheet as of January 1, 2018:

	As of January 1, 2018
	As revised under ASC 606			As originally reported			Effect of change
Assets:
Unbilled - collaboration and license revenue	$	6,694		$	—		$	6,694
Trade and other receivables, net		2,706			—			2,706
Prepaid expenses and other current assets		—			2,706			(2,706	)
Liabilities:
Deferred revenue, current portion		6,354			11,169			(4,815	)
Deferred revenue, long-term		1,269			18,798			(17,529	)
Stockholders' equity:
Accumulated deficit	$	(1,175,481	)	$	(1,204,519	)	$	29,038

The following table compares the reported condensed consolidated balance sheet and statement of operations information to the balances that do not reflect the adoption of ASC 606 as of and for the three months ended March 31, 2018:

	As of March 31, 2018
	As reported			Balances without the adoption of ASC 606			Effect of change
Assets:
Unbilled - collaboration and license revenue	$	4,660		$	—		$	4,660
Trade and other receivables, net		968			—			968
Prepaid expenses and other current assets		—			968			(968	)
Liabilities:
Deferred revenue, current portion		3,861			9,547			(5,686	)
Deferred revenue, long-term		5,412			23,064			(17,652	)
Stockholders' equity:
Accumulated deficit		(1,259,660	)		(1,287,659	)		27,999

	Three Months Ended March 31, 2018
	As reported			Balances without the adoption of ASC 606			Effect of change
Revenue:
Collaboration and license revenue	$	6,038		$	6,354		$	(316	)
Operating expenses:
Research and development		60,067			59,345			722
Loss from operations		(85,300	)		(84,262	)		(1,038	)
Net loss		(84,510	)		(83,472	)		(1,038	)
Net loss attributable to Portola		(84,178	)		(83,140	)		(1,038	)
Net loss per share attributable to Portola common stockholders: Basic and diluted	$	(1.28	)	$	(1.27	)	$	(0.01	)