Fair Value Measurements (Details 3) (USD $)
In Thousands, unless otherwise specified |
Oct. 31, 2012
|
Jan. 31, 2012
|
---|---|---|
Cost | $ 97,779 | $ 92,492 |
Gross Unrealized Gains | 67 | 88 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 97,846 | 92,580 |
Cash [Member]
|
||
Cost | 81,969 | 74,226 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 81,969 | 74,226 |
Cash equivalents [Member]
|
||
Cost | 3,089 | 6,359 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 3,089 | 6,359 |
Cash and cash equivalents [Member]
|
||
Cost | 85,058 | 80,585 |
Gross Unrealized Gains | 0 | 0 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 85,058 | 80,585 |
Us Government Agency Issues Short Term [Member]
|
||
Cost | 2,004 | 6,781 |
Gross Unrealized Gains | 41 | 68 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 2,045 | 6,849 |
Corporate debt securities [Member]
|
||
Cost | 0 | 1,000 |
Gross Unrealized Gains | 0 | 6 |
Estimated Fair Value | 0 | 1,006 |
Marketable securities-short-term [Member]
|
||
Cost | 2,004 | 7,781 |
Gross Unrealized Gains | 41 | 74 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 2,045 | 7,855 |
Us Government Agency Issues Long Term [Member]
|
||
Cost | 10,717 | 4,126 |
Gross Unrealized Gains | 26 | 14 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | 10,743 | 4,140 |
Marketable securities - long-term [Member]
|
||
Cost | 10,717 | 4,126 |
Gross Unrealized Gains | 26 | 14 |
Gross Unrealized Losses | 0 | 0 |
Estimated Fair Value | $ 10,743 | $ 4,140 |