| 2013 | 2012 | ||||||||||||
| Benefit | Plan | Benefit | Plan | ||||||||||
| At December 31: | Obligation | Assets | Obligation | Assets | |||||||||
| Plans with PBO in excess of plan assets | $ | 41,003 | $ | 29,223 | $ | 99,184 | $ | 83,799 | |||||
| Plans with ABO in excess of plan assets | 40,315 | 29,213 | 98,263 | 83,677 | |||||||||
| Plans with assets in excess of PBO | 58,651 | 64,194 | 6,944 | 7,889 | |||||||||