Pension Benefits | Other Benefits | ||||||||||||||
2013 | 2012 | 2013 | 2012 | ||||||||||||
Benefit obligation at beginning of year | $ | 1,948.5 | $ | 1,851.3 | $ | 623.0 | $ | 651.3 | |||||||
Service cost | 14.2 | 16.4 | 6.7 | 6.8 | |||||||||||
Interest cost | 67.8 | 76.4 | 22.4 | 27.5 | |||||||||||
Actuarial (gain) loss | (129.9 | ) | 129.6 | 4.8 | (28.4 | ) | |||||||||
Benefits paid | (135.9 | ) | (125.2 | ) | (49.4 | ) | (34.2 | ) | |||||||
Benefit obligation at end of year | $ | 1,764.7 | $ | 1,948.5 | $ | 607.5 | $ | 623.0 | |||||||