Employee Benefit Plans

We sponsor various noncontributory defined benefit pension plans covering substantially all full-time employees that began employment prior to June 30, 2008. Benefits earned by employees are generally based upon employee compensation and years of service credits. We also have a non-qualified Supplemental Executive Retirement Plan ("SERP"). Effective June 30, 2009, we froze the accrual of benefits under our defined benefit pension plans and our SERP that cover the majority of our employees.

We sponsor a defined contribution plan covering substantially all non-union and certain union employees. We match a portion of employees' voluntary contributions to this plan. In connection with freezing the accrual of service credits under certain of our defined benefit pension plans, we began contributing additional amounts to certain employees' defined contribution retirement accounts in 2011. These transition credits, which will be made through 2015, are determined based upon the employee’s age, compensation and years of service.

Other union-represented employees are covered by defined benefit pension plans jointly sponsored by us and the union, or by union-sponsored multi-employer plans.

The components of the expense consisted of the following:



	Three Months Ended September 30,						Nine Months Ended September 30,
(in thousands)	2014			2013			2014			2013

Service cost	$	21		$	17		$	64		$	51
Interest cost	6,600			5,976			19,155			17,927
Expected return on plan assets, net of expenses	(5,893		)	(5,371		)	(17,611		)	(16,113		)
Amortization of actuarial loss	862			1,060			2,145			3,182
Total for defined benefit plans	1,590			1,682			3,753			5,047
Multi-employer plans	100			95			324			326
Withdrawal from GCIU multi-employer plan	—			—			4,100			—
SERP	80			808			672			1,981
Defined contribution plans	2,419			2,341			8,635			8,627
Net periodic benefit cost	$	4,189		$	4,926		$	17,484		$	15,981

We contributed $0.6 million to fund current benefit payments for our SERP during the nine months ended September 30, 2014. We anticipate contributing an additional $0.2 million to fund the SERP’s benefit payments during the remainder of 2014. We contributed $0.1 million to our defined benefit pension plans during the first nine months of 2014.

We participate in multi-employer pension plans that cover certain employees that are members of unions or trade associations that have a collective bargaining agreement with us. In the second quarter of 2014, unions ratified our plan to withdraw from the Graphics Communication International Union (GCIU) Employer Retirement Fund. Upon ratification of the agreement, we estimated the undiscounted liability to be approximately $6.5 million and recorded a liability of $4.1 million for the present value withdrawal liability. Once the final withdrawal liability is determined at the end of this year with the GCIU, we either will pay the liability in a lump sum or make equal monthly installments over 20 years beginning in 2015.