Summary of Significant Accounting Policies (Tables)

6 Months Ended

Jun. 30, 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 restricted cash, and consists of the following (in thousands):

	June 30, 2018		December 31, 2017		June 30, 2017		December 31, 2016
Cash and cash equivalents	$	173,052	$	181,568	$	123,837	$	188,480
Restricted cash (SRX Cardio)		30		173		172		178
Total cash balance in condensed consolidated statements of cash flows	$	173,082	$	181,741	$	124,009	$	188,658

Percentage of Revenue from Significant Customers

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

	Three Months Ended June 30,		Six Months Ended June 30,
	2018	2017	2018	2017
Bayer Pharma, AG and Janssen Pharmaceuticals, Inc.	48%	53%	48%	47%
Daiichi Sankyo, Inc.	*	14%	18%	15%
Bristol-Myers Squibb Company and Pfizer Inc.	*	27%	*	31%

* Less than 10%

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 (in thousands):

	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 and six months ended June 30, 2018 (in thousands, except for per share data):

	As of June 30, 2018
	As Reported			Balances Without the Adoption of ASC 606			Effect of Change
Assets:
Unbilled - collaboration and license revenue	$	6,491		$	—		$	6,491
Trade and other receivables, net		847			—			847
Prepaid expenses and other current assets		—			847			(847	)
Liabilities:
Deferred revenue, current portion		4,928			5,726			(798	)
Deferred revenue, long-term		5,194			25,316			(20,122	)
Stockholders' equity:
Accumulated deficit		(1,365,853	)		(1,393,264	)		27,411

	Three Months Ended June 30, 2018
	As Reported			Balances Without the Adoption of ASC 606			Effect of Change
Revenue:
Collaboration and license revenue	$	1,746		$	1,569		$	177
Operating expenses:
Research and development		66,440			65,676			764
Loss from operations		(103,695	)		(103,107	)		(588	)
Net loss		(105,971	)		(105,383	)		(588	)
Net loss attributable to Portola		(106,194	)		(105,606	)		(588	)
Net loss per share attributable to Portola common stockholders: Basic and diluted	$	(1.61	)	$	(1.60	)	$	(0.01	)

	Six Months Ended June 30, 2018
	As Reported			Balances Without the Adoption of ASC 606			Effect of Change
Revenue:
Collaboration and license revenue	$	7,784		$	7,925		$	(141	)
Operating expenses:
Research and development		126,507			125,021			1,486
Loss from operations		(188,995	)		(187,368	)		(1,627	)
Net loss		(190,481	)		(188,854	)		(1,627	)
Net loss attributable to Portola		(190,372	)		(188,745	)		(1,627	)
Net loss per share attributable to Portola common stockholders: Basic and diluted	$	(2.90	)	$	(2.87	)	$	(0.03	)