| Financial Instruments |
Financial Instruments We invest our excess cash in a variety of marketable securities, which are all classified as available-for-sale. The following summarizes our cash and cash equivalents, restricted cash and cash equivalents and marketable securities by financial instrument category as of the respective period ends: | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | May 31, 2016 | ($ in thousands) | Amortized Cost | | Unrealized Gains | | Unrealized Losses | | Fair Value | | Cash and Cash Equivalents(1) | | Current Marketable Securities | | Noncurrent Marketable Securities | Cash | $ | 408,823 |
| | $ | — |
| | $ | — |
| | $ | 408,823 |
| | $ | 408,823 |
| | $ | — |
| | $ | — |
| Level 1: | | | | | | | | | | | | | | Money market funds | 111,236 |
| | — |
| | — |
| | 111,236 |
| | 111,236 |
| | — |
| | — |
| Level 2: | | | | | | | | | | | | | | Corporate bonds | 113,004 |
| | 30 |
| | (155 | ) | | 112,879 |
| | — |
| | 96,531 |
| | 16,348 |
| Tax-exempt municipal bonds | 104,281 |
| | 33 |
| | (43 | ) | | 104,271 |
| | 600 |
| | 84,324 |
| | 19,347 |
| Time deposits | 50,458 |
| | — |
| | — |
| | 50,458 |
| | 25,187 |
| | 25,271 |
| | — |
| Other | 40,797 |
| | 12 |
| | (6 | ) | | 40,803 |
| | 1,000 |
| | 36,175 |
| | 3,628 |
| Total | $ | 828,599 |
| | $ | 75 |
| | $ | (204 | ) | | $ | 828,470 |
| | $ | 546,846 |
| | $ | 242,301 |
| | $ | 39,323 |
|
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | August 31, 2015 | ($ in thousands) | Amortized Cost | | Unrealized Gains | | Unrealized Losses | | Fair Value | | Cash and Cash Equivalents(1) | | Current Marketable Securities | | Noncurrent Marketable Securities | Cash | $ | 564,225 |
| | $ | — |
| | $ | — |
| | $ | 564,225 |
| | $ | 564,225 |
| | $ | — |
| | $ | — |
| Level 1: | | | | | | | | | | | | | | Money market funds | 107,408 |
| | — |
| | — |
| | 107,408 |
| | 107,408 |
| | — |
| | — |
| Level 2: | | | | | | | | | | | | | | Corporate bonds | 137,283 |
| | 16 |
| | (271 | ) | | 137,028 |
| | 1,823 |
| | 82,047 |
| | 53,158 |
| Tax-exempt municipal bonds | 97,022 |
| | 68 |
| | (60 | ) | | 97,030 |
| | 2,408 |
| | 61,530 |
| | 33,092 |
| Time deposits | 50,267 |
| | — |
| | — |
| | 50,267 |
| | 25,110 |
| | 25,157 |
| | — |
| Other | 36,634 |
| | 10 |
| | (37 | ) | | 36,607 |
| | 1,100 |
| | 25,942 |
| | 9,565 |
| Total | $ | 992,839 |
| | $ | 94 |
| | $ | (368 | ) | | $ | 992,565 |
| | $ | 702,074 |
| | $ | 194,676 |
| | $ | 95,815 |
|
(1) Cash and cash equivalents includes restricted cash and cash equivalents. We measure our financial instruments at fair value on a recurring basis as follows: | | • | Money market funds - We use Level 1 inputs that primarily consist of real-time quotes for transactions in active exchange markets involving identical assets. |
| | • | Other financial instruments - We use a market approach with Level 2 observable inputs for all other securities. The Level 2 inputs include quoted prices for similar assets in active markets, or quoted prices for identical or similar assets in markets that are not active. |
Our marketable securities have maturities that occur within three years. We may sell certain of our marketable securities prior to their stated maturities for strategic reasons including, but not limited to, investment yield and credit risk management. We have not recognized significant gains or losses related to such sales. |