2010 10-K: Part II 2008 Segment Information Year ended December 31, 2008 Investment  Investment  Corporate  ($000) Information  Management  Items  Total Revenue  $ 390,693  $ 111,764  $  —  $ 502,457 Operating expense, excluding stock-based compensation expense, depreciation, and amortization  241,678  49,010  35,616   326,304 Stock-based compensation expense  5,271  1,997  4,013  11,281 Depreciation and amortization  5,085  361  20,550  25,996 Operating income (loss)  $ 138,659  $ 60,396  $ (60,179)  $ 138,876 Capital expenditures  $ 34,878  $  5,991  $  7,650  $  48,519 U.S. revenue  $ 381,021 Non-U.S. revenue  $ 121,436 As of December 31, 2008 Goodwill  $ 155,772  $ 31,470  $  —  $ 187,242 U.S. long-lived assets  $ 45,763 Non-U.S. long-lived assets  $  13,059 As of December 31 ($000)  2010 2009 Available-for-sale $ 173,072 $ 197,306 Held-to-maturity  7,476 10,588 Trading securities  4,692 4,163 Total  $ 185,240 $ 212,057  Unrealized   Unrealized  Fair  ($000)  Cost  Gain  Loss  Value As of December 31, 2010 Available-for-sale: Government obligations  $ 113,597  $  36  $ (56)  $ 113,577 Corporate bonds 42,839  63   (24)  42,878 Commercial paper  2,994  —  (3)  2,991 Equity securities 4,510  418  (6)  4,922 Mutual funds  8,146  558  —  8,704 Total  $172,086  $ 1,075  $ (89)  $173,072 Held-to-maturity: Certificates of deposit  $  7,476  $  —  $ —  $  7,476 As of December 31, 2009 Available-for-sale: Government obligations  $174,433   $  439   $ (50)  $ 174,822 Corporate bonds 12,268  44  (1)  12,311 Commercial paper  —  —  —  — Equity securities 2,013  188   (28)  2,173  Mutual funds  8,000  —  —  8,000  Total  $ 196,714   $  671   $ (79)  $ 197,306 Held-to-maturity: Certificates of deposit  $ 10,588   $  —   $ —   $ 10,588 6. Investments and Fair Value Measurements We classify our investments in three categories: available-for-sale,  held-to-maturity, and trading. We monitor the concentration, diver- sification, maturity, and liquidity of our investment portfolio, which  is primarily invested in fixed-income securities, and classify our  investment portfolio as shown below: The following table shows the cost, unrealized gains (losses), and  fair values related to investments classified as available-for-sale  and held-to-maturity: 114