Condensed Balance Sheets (Parentheticals) (USD $) In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts	$ 0	$ 0
Par Value (in dollars per share)	$ 0.001	$ 0.001
Shares Authorized (in shares)	40,000	40,000
Shares Issued (in shares)	14,517	14,508
Shares Outstanding (in shares)	14,517	14,508
Treasury stock (in shares)	2,550	2,503
3/4% convertible senior subordinated notes due 2023 | Convertible Senior Subordinated Notes
Interest rate (as a percent)	0.75%	0.75%