|
Investment Securities Continuous Unrealized Loss (Details) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | 6 Months Ended | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Jun. 30, 2013
Corporate Bonds
|
Dec. 31, 2012
Corporate Bonds
|
Jun. 30, 2013
Commercial Paper
|
Dec. 31, 2012
Commercial Paper
|
Jun. 30, 2013
Agencies Securities
|
Dec. 31, 2012
Agencies Securities
|
Jun. 30, 2013
Mortgage-backed Securities
|
Jun. 30, 2013
Municipal Bonds
|
Dec. 31, 2012
Municipal Bonds
|
Jun. 30, 2013
Asset-backed Securities
|
Jun. 30, 2013
Total fixed income securities [Member]
|
Dec. 31, 2012
Total fixed income securities [Member]
|
|
| Schedule of Available-for-sale Securities [Line Items] | ||||||||||||||||
| Other than Temporary Impairment Losses, Investments | $ 0 | $ 0 | $ 0 | $ 0 | ||||||||||||
| Fair value, less than 12 months | 19,226 | 6,138 | 8,384 | 6,390 | 13,488 | 6,302 | 1,147 | 11,599 | 1,602 | 9,846 | 63,690 | 20,432 | ||||
| Unrealized losses, less than 12 months | (25) | (2) | (2) | (2) | (18) | (1) | (59) | (30) | (3) | (21) | (155) | (8) | ||||
| Fair value, 12 months or more | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||
| Unrealized losses, 12 months or more | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||
| Total fair value | 19,226 | 6,138 | 8,384 | 6,390 | 13,488 | 6,302 | 1,147 | 11,599 | 1,602 | 9,846 | 63,690 | 20,432 | ||||
| Total unrealized losses | $ (25) | $ (2) | $ (2) | $ (2) | $ (18) | $ (1) | $ (59) | $ (30) | $ (3) | $ (21) | $ (155) | $ (8) | ||||