Table of Contents 118 December 31, 2018 (Millions of dollars) Level 1 Level 2 Level 3 Measured at NAV Total Assets at Fair Value Other Postretirement Benefits Equity securities: U.S. equities $ 151 $ 1 $ — $ — $ 152 Non-U.S. equities 64 — — — 64 Fixed income securities: U.S. corporate bonds — 45 — — 45 Non-U.S. corporate bonds — 11 — — 11 U.S. government bonds — 8 — — 8 U.S. governmental agency mortgage-backed securities — 25 — — 25 Non-U.S. government bonds — 3 — — 3 Cash, short-term instruments and other 3 1 — 16 20 Total other postretirement benefit assets $ 218 $ 94 $ — $ 16 $ 328 December 31, 2017 (Millions of dollars) Level 1 Level 2 Level 3 Measured at NAV Total Assets at Fair Value Other Postretirement Benefits Equity securities: U.S. equities $ 255 $ 1 $ — $ — $ 256 Non-U.S. equities 103 — — — 103 Fixed income securities: U.S. corporate bonds — 60 — 1 61 Non-U.S. corporate bonds — 15 — — 15 U.S. government bonds — 17 — — 17 U.S. governmental agency mortgage-backed securities — 34 — — 34 Non-U.S. government bonds — 4 — — 4 Cash, short-term instruments and other — 3 — 11 14 Total other postretirement benefit assets $ 358 $ 134 $ — $ 12 $ 504