Employee Benefit Plans

3 Months Ended

Mar. 31, 2012

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, 2012 and 2011 the components of pension expense are as follows:

	Three Months Ended March 31
	2012			2011
Service cost	$	2,827		$	2,571
Interest cost	4,496			4,507
Expected return on assets	(5,379		)	(5,535		)
Amortization of prior service cost	53			39
Amortization of net actuarial loss	2,737			1,213
Total pension expense	$	4,734		$	2,795

The assumed discount rate for 2012 is 4.75 percent, the expected long-term rate of return on plan assets is 7.50 percent and the assumed rate of salary increases is 4.00 percent. For 2011 the assumed discount rate was 5.50 percent, expected long-term rate of return was 7.75 percent and the assumed rate of salary increases was 4.50 percent.