Pension Plans | Other Postretirement Benefit Plans | ||||||||||||||||||||||
Years Ended December 31 | 2013 | 2012 | 2011 | 2013 | 2012 | 2011 | |||||||||||||||||
Net gain (loss) arising during the period | $ | 3,189 | $ | (1,907 | ) | $ | (1,628 | ) | $ | 499 | $ | (24 | ) | $ | 106 | ||||||||
Prior service credit (cost) arising during the period | 203 | (13 | ) | 783 | 26 | 78 | 133 | ||||||||||||||||
$ | 3,392 | $ | (1,920 | ) | $ | (845 | ) | $ | 525 | $ | 54 | $ | 239 | ||||||||||
Net loss amortization included in benefit cost | $ | 407 | $ | 256 | $ | 196 | $ | 23 | $ | 31 | $ | 38 | |||||||||||
Prior service (credit) cost amortization included in benefit cost | (71 | ) | (71 | ) | 5 | (73 | ) | (66 | ) | (55 | ) | ||||||||||||
$ | 336 | $ | 185 | $ | 201 | $ | (50 | ) | $ | (35 | ) | $ | (17 | ) | |||||||||