Three Months Ended March 31, 2015 | Year Ended Dec. 31 | ||||||||||||||||||||||
| 2014 | 2013 | 2012 | 2011 | 2010 | |||||||||||||||||||
| Earnings, as defined: | |||||||||||||||||||||||
| Pretax income from operations | $ | 35,331 | $ | 113,045 | $ | 95,877 | $ | 79,509 | $ | 84,620 | $ | 68,861 | |||||||||||
| Add: Fixed charges | 7,836 | 29,686 | 28,325 | 25,215 | 24,628 | 24,897 | |||||||||||||||||
| Total earnings, as defined | $ | 43,167 | $ | 142,731 | $ | 124,202 | $ | 104,724 | $ | 109,248 | $ | 93,758 | |||||||||||
| Fixed charges, as defined: | |||||||||||||||||||||||
| Interest charges | $ | 7,756 | $ | 29,273 | $ | 27,797 | $ | 24,799 | $ | 24,168 | $ | 24,517 | |||||||||||
| Interest component of leases | 80 | 413 | 528 | 416 | 460 | 380 | |||||||||||||||||
| Total fixed charges, as defined | $ | 7,836 | $ | 29,686 | $ | 28,325 | $ | 25,215 | $ | 24,628 | $ | 24,897 | |||||||||||
| Ratio of earnings to fixed charges | 5.5 | 4.8 | 4.4 | 4.2 | 4.4 | 3.8 | |||||||||||||||||
