XML 98 R74.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Retirement Savings Plan - Additional Information (Detail) (USD $) | 12 Months Ended
--- | ---
Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items] |  |  |
Employer matching contributions vesting period | 2 years |  |
United States [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Employer matching contributions | $ 1,000,000 | $ 1,200,000 | $ 1,100,000
Canada [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Employer matching contributions | $ 157,000 | $ 232,000 | $ 280,000

X
- Definition Defined contribution plan employers matching contribution vesting period. + References No definition available. + Details
Name: | nvtl_DefinedContributionPlanEmployersMatchingContributionVestingPeriod
Namespace Prefix: | nvtl_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The increase in the fair value of plan assets from contributions made by the employer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=28361610&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration