Note 5 - Stock-Based Compensation (Detail) - Tax Short-Fall From Share-Based Payment Arrangements (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Short-fall of tax deductions in excess of grant-date fair value	$ (69)	$ (565)
Benefit of tax deductions on grant-date fair value	596	663
Total benefit of tax deductions	$ 527	$ 98

Amount of excess tax benefit (tax deficiency) that arises when compensation cost from non-qualified equity-based compensation recognized on the entity's tax return exceeds (is less than) compensation cost from equity-based compensation recognized in financial statements. Excess tax benefit (tax deficiency) reduces (increases) net cash provided by operating activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 20

-Section 55

-Paragraph 24

-URI http://asc.fasb.org/extlink&oid=6576910&loc=d3e11374-113907

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration