Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Cash flows from operating activities:
Net loss	$ (4,584)	$ (20,185)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,589	1,121
Accretion of premium on marketable investment securities	1,760	1,068
Shares issued for payment of services	0	549
Non-cash interest expense	4,314	5,955
Non-cash royalties	(20,317)	(19,784)
Compensation expense on share-based awards	7,588	5,062
Realized gain on sale of marketable investment securities	(7)	(2)
(Increase) decrease in operating assets:
Accounts receivable	(1,650)	(4,108)
Inventory	(2,645)	6,573
Prepaid expenses, other current assets and other assets	(1,651)	460
(Decrease) increase in operating liabilities:
Accounts payable and accrued expenses	644	6,288
Other liabilities	2,210	(1,159)
Net cash used in operating activities	(12,749)	(18,162)
Cash flows from investing activities:
Sales of marketable investment securities	3,426	4,501
Maturities of marketable investment securities	74,533	42,156
Purchases of marketable investment securities	(66,589)	(74,888)
Acquisitions of property and equipment	(1,066)	(364)
Net cash provided by (used in) investing activities	10,304	(28,595)
Cash flows from financing activities:
Net proceeds from the sale of common stock	0	93,454
Net proceeds from the exercise of stock options	6,612	6,585
Excess tax benefit from stock options	122	0
Shares withheld for the payment of taxes	(1,995)	(574)
Net cash provided by financing activities	4,739	99,465
Effect of exchange rate changes on cash	(191)	9
Net increase in cash and cash equivalents	2,103	52,717
Cash and cash equivalents at beginning of period	51,204	17,471
Cash and cash equivalents at end of period	53,307	70,188
Supplemental Disclosures of Cash Flow Information
Cash paid for interest	256	472
Cash paid for income taxes	84	0
Supplemental Disclosure of Non-cash Investing and Financing Activities
6.1 million shares of NPS common stock issued in connection with the Takeda Termination and Transition agreement	0	55,403
Unrealized (loss) gain on marketable investment securities	28	75
Accrued acquisition of property and equipment	500	114
Noncash reductions of debt	15,640	12,667
Conversion of 5.75% convertible notes	$ 16,535	$ 0