Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net income:	$ 4,277,103	$ 2,338,236
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	892,407	818,920
Stock-based compensation expense	307,425	250,071
Deferred tax expense	7,566	(112,403)
Loss (gain) on revaluation of contingent consideration	98,320	(53,974)
Changes in assets and liabilities:
Accounts receivable	(94,064)	(2,772,175)
Royalties and other receivables	6,730,818	5,284,800
Inventories	331,087	872,260
Prepaid expenses and other current assets	(209,701)	(51,472)
Accounts payable	(236,176)	(548,648)
Accrued liabilities	(3,999,779)	(1,301,152)
Long-term liabilities	(106,216)	(1,129,760)
Net cash provided by operating activities	7,998,790	3,594,703
Cash flows from investing activities:
Purchases of marketable securities	(8,970,763)	(10,538,701)
Redemptions of marketable securities	10,529,183	5,811,555
Purchases of property, plant and equipment	(596,788)	(322,099)
Net cash provided by (used in) investing activities	961,632	(5,049,245)
Cash flows from financing activities:
Exercise of stock options	497,709	956,721
Net cash provided by financing activities	497,709	956,721
Effect of exchange rate changes on cash and cash equivalents	(78,163)	(141,985)
Net increase (decrease) in cash and cash equivalents	9,379,968	(639,806)
Cash and cash equivalents, beginning of period	39,829,653	29,209,821
Cash and cash equivalents, end of period	49,209,621	28,570,015
Supplemental disclosure of non-cash investing activities:
Income taxes paid	$ 466,000	$ 659,000