As of March 31, 2013

Amortized
Cost

Gross
Unrealized
Gains

Gross
Unrealized
Losses

Fair
Value

Municipal obligations

$

606

$

26

$

—

$

632

U.S. government securities funds

995

—

(8

)

987

Equity securities

227

267

(3

)

491

Total short-term investment securities

$

1,828

$

293

$

(11

)

$

2,110

As of December 31, 2012

Amortized
Cost

Gross
Unrealized
Gains

Gross
Unrealized
Losses

Fair
Value

Municipal obligations

$

608

$

30

$

—

$

638

U.S. government securities funds

995

—

(9

)

986

Equity securities

227

228

(8

)

447

Total short-term investment securities

$

1,830

$

258

$

(17

)

$

2,071