Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities
Net loss	$ (80,147)	$ (76,276)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,664	1,319
Change in valuation of warrant liability	47	(72)
Non-cash interest expense	2,941
Amortization of premiums on investments	1,140	915
Amortization of debt issuance costs	147
Share-based compensation expense	17,651	18,076
Benefit for deferred income taxes	(244)
Unrealized foreign currency transaction losses, net	963
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,163	(356)
Trade receivables, net	(8,480)	(669)
Deposits and other assets	(170)	258
Accounts payable and accrued expenses	(3,435)	(6,039)
Other long-term liabilities	1	(46)
Deferred revenue	587	(3,354)
Net cash used in operating activities	(66,172)	(66,244)
Cash flows from investing activities
Purchases of fixed assets	(275)	(1,177)
Purchases of marketable securities	(46,256)	(44,988)
Sale and redemption of marketable securities	89,645	83,468
Net cash provided by investing activities	43,114	37,303
Cash flows from financing activities
Proceeds from exercise of options	34	8,072
Net cash provided by financing activities	34	8,072
Effect of exchange rate changes on cash	660	341
Net decrease in cash and cash equivalents	(22,364)	(20,528)
Cash and cash equivalents, beginning of period	58,022	49,748
Cash and cash equivalents, end of period	35,658	29,220
Supplemental disclosure of cash information
Cash paid for interest	2,263
Cash paid for income taxes	264
Supplemental disclosures of non-cash information related to investing and financing activities
Change in unrealized gain (loss) on marketable securities, net of tax	$ 618	$ (99)

Represents change in the unrealized gain (loss) on marketable securities in noncash investing and financing activities.

No definition available.

Name:	ptct_ChangeInUnrealizedGainLossOnMarketableSecurities
Namespace Prefix:	ptct_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The sum of the periodic adjustments of the differences between securities' face values and purchase prices that are charged against earnings. This is called accretion if the security was purchased at a discount and amortization if it was purchased at premium. As a noncash item, this element is an adjustment to net income when calculating cash provided by or used in operations using the indirect method.