Employee Benefit Plans

3 Months Ended

Mar. 31, 2013

General Discussion of Pension and Other Postretirement Benefits [Abstract]

Employee Benefit Plans

Employee Benefit Plans

Pension expense is a component of employee benefits expense. For the three-month periods ended March 31, 2013, and 2012 the components of pension expense are as follows:

	Three months ended March 31
	2013			2012
Service cost	$	4,222		$	2,827
Interest cost	5,895			4,496
Expected return on assets	(6,931		)	(5,379		)
Amortization of prior service cost	53			53
Amortization of net actuarial loss	4,251			2,737
Total pension expense	$	7,490		$	4,734

The assumed discount rate for 2013 is 4.00 percent, the expected long-term rate of return on plan assets is 7.25 percent, and the assumed rate of salary increases is 4.00 percent. For 2012 the assumed discount rate was 4.75 percent, expected long-term rate of return was 7.50 percent and the assumed rate of salary increases was 4.00 percent.