Note 3 - Taxation (Detail) - Summary of Deferred Tax Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Deferred tax assets:
Stock compensation expense	$ 7,936	$ 7,734
Alternative minimum tax credit	71	71
Warranty reserve	291	118
Accounts receivable	65	161
Vacation accrual	157	118
Commissions and other accruals	205
Deferred rent liability	53	47
Equipment	69
Intangible assets	778	603
Net operating loss carryforwards	1,868	1,327
Total deferred tax assets	11,493	10,179
Deferred tax liabilities:
Equipment	(1,466)	(1,513)
Prepaid expenses	(200)	(285)
Patents	(489)	(384)
Goodwill	(3,193)	(2,689)
Other	(16)	(20)
Total deferred tax liabilities	(5,364)	(4,891)
Net deferred tax asset before valuation allowance	6,129	5,288
Valuation allowances for deferred tax assets	(1,868)	(1,327)	(1,102)	(1,177)
Net deferred tax asset	$ 4,261	$ 3,961