Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net loss	$ (142,110)	$ (170,447)	$ (93,753)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	3,290	2,876	2,235
Change in valuation of warrant liability	(47)	(140)	130
Amortization of premiums on investments	1,885	2,480	1,607
Amortization of debt issuance costs	302	107	0
Share-based compensation expense	35,009	33,979	19,310
Non-cash interest expense	6,065	2,146	0
Disposal of asset	0	(37)	0
Benefit for deferred income taxes	(199)	0	0
Unrealized foreign currency transaction losses, net	1,202	0	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,171	(2,107)	(2,286)
Trade receivables, net	(14,842)	(6,907)	(3,487)
Deposits and other assets	(278)	131	(340)
Accounts payable and accrued expenses	4,259	16,981	16,914
Other long-term liabilities	(799)	(92)	(80)
Deferred revenue	1,526	(3,307)	2,476
Net cash used in operating activities	(103,566)	(124,337)	(57,274)
Cash flows from investing activities
Purchases of fixed assets	(1,776)	(2,720)	(4,664)
Purchases of marketable securities	(85,377)	(223,762)	(247,804)
Sale & redemption of marketable securities	191,634	205,671	107,300
Net cash provided by (used in) investing activities	104,481	(20,811)	(145,168)
Cash flows from financing activities
Payments on long-term debt	0	0	(49)
Proceeds from exercise of options	968	8,711	1,196
Net proceeds from public offerings	0	0	235,979
Debt issuance costs related to convertible notes	0	(4,650)	0
Proceeds from issuance of convertible notes	0	150,000	0
Net cash provided by financing activities	968	154,061	237,126
Effect of exchange rate changes on cash	(1,584)	(639)	(350)
Net increase in cash and cash equivalents	299	8,274	34,334
Cash and cash equivalents, beginning of period	58,022	49,748	15,414
Cash and cash equivalents, end of period	58,321	58,022	49,748
Supplemental disclosure of cash information
Cash paid for interest	4,513	0	1
Cash paid for income taxes	943	111	0
Supplemental disclosures of non-cash information related to investing and financing activities
Change in unrealized gain (loss) on marketable securities	$ 386	$ (202)	$ (457)

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.