The components of other intangible assets were as follows:
| 2013 | 2012 | |||||||||||||||||
| (Millions) | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | Gross Carrying Amount | Accumulated Amortization | Net Carrying Amount | ||||||||||||
| Customer relationships(a) | $ | 1,297 | $ | (660) | $ | 637 | $ | 1,238 | $ | (526) | $ | 712 | ||||||
| Other | 269 | (89) | 180 | 428 | (147) | 281 | ||||||||||||
| Total | $ | 1,566 | $ | (749) | $ | 817 | $ | 1,666 | $ | (673) | $ | 993 | ||||||