2.2.0.25falsefalse006110 - Disclosure - Employee retirement plantruefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010
USD ($)
USD ($) / shares
$c00026http://www.sec.gov/CIK0000935494duration2010-01-01T00:00:002010-12-31T00:00:00u000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u001Standardhttp://www.xbrl.org/2003/instancesharesxbrli0u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0nati_NotesToFinancialStatementsAbstractnatifalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalse3false0nati_EmployeeRetirementPlanTextBlocknatifalsenadurationDisclosure of the deferred salary arrangement under Section 401(k) of the Internal Revenue Code.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1falsefalsefalse00<div style="TEXT-INDENT: 0pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt; FONT-WEIGHT: bold">Note 11 – Employee retirement plan</font></div><div style="TEXT-INDENT: 0pt; DISPLAY: block"><br /></div><div style="TEXT-INDENT: 27pt; DISPLAY: block; MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt" align="justify"><font style="DISPLAY: inline; FONT-FAMILY: Times New Roman; FONT-SIZE: 10pt">We have a defined contribution retirement plan pursuant to Section 401(k) of the Internal Revenue Code. Substantially all domestic employees with at least 30 days of continuous service are eligible to participate and may contribute up to 15% of their compensation. The Board of Directors has elected to make matching contributions equal to 50% of employee contributions, which may be applied to a maximum of 6% of each participant’s compensation. Employees are eligible for matching contributions after one year of continuous service. Company contributions vest immediately. Our policy prohibits participants from direct investment in shares of our common stock within the plan. Company contributions charged to expense were $4.4 million, $3.9 million and $3.7 million in 2010, 2009 and 2008, respectively.</font></div>Note 11 – Employee retirement planWe have a defined contribution retirement plan pursuant to Section 401(k) of the Internal Revenue Code. SubstantiallyfalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDisclosure of the deferred salary arrangement under Section 401(k) of the Internal Revenue Code.No authoritative reference available.falsefalse12Employee retirement planUnKnownUnKnownUnKnownUnKnownfalsetrue