XML 83 R34.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Stock-Based Compensation (Tables) | 3 Months Ended
--- | ---
Apr. 05, 2015
Schedule of Estimated Fair Value TSR Performance-Based Restricted Stock Unit Awards Assumptions | The fair value was estimated using the Monte Carlo simulation model with the following assumptions:
|  | For the Three Months Ended |
|  | April 5, 2015 |  |  | March 30, 2014 |
Risk-free interest rate |  |  | 0.77 | % |  |  | 0.75 | %
Teradyne volatility-historical |  |  | 28.2 | % |  |  | 36.1 | %
Philadelphia Semiconductor Index volatility-historical |  |  | 19.7 | % |  |  | 24.6 | %
Dividend yield |  |  | 1.33 | % |  |  | 1.25 | %
Stock Options |
Fair Value of Stock Options Using Assumptions | The fair value of stock options was estimated using the Black-Scholes option-pricing model with the following assumptions:
|  | For the Three Months Ended |
|  | April 5, 2015 |  |  | March 30, 2014 |
Expected life (years) |  |  | 4.0 |  |  |  | 4.0 |
Risk-free interest rate |  |  | 1.1 | % |  |  | 1.2 | %
Volatility-historical |  |  | 33.4 | % |  |  | 38.8 | %
Dividend yield |  |  | 1.33 | % |  |  | 1.25 | %

X
- Definition Schedule Of Share Based Payment Award Shareholder Return Plan Valuation Assumptions Table [Text Block] + References No definition available. + Details
Name: | ter_ScheduleOfShareBasedPaymentAwardShareholderReturnPlanValuationAssumptionsTableTextBlock
Namespace Prefix: | ter_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the significant assumptions used during the year to estimate the fair value of stock options, including, but not limited to: (a) expected term of share options and similar instruments, (b) expected volatility of the entity's shares, (c) expected dividends, (d) risk-free rate(s), and (e) discount for post-vesting restrictions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ScheduleOfShareBasedPaymentAwardStockOptionsValuationAssumptionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |