Pension Plan (Tables)

9 Months Ended

Sep. 30, 2012

Compensation and Retirement Disclosure [Abstract]

Schedule of net benefit cost

Net periodic pension costs consist of the following:

	Three months ended September 30,						Nine months ended September 30,
	2011			2012			2011			2012
Service cost	$	70		$	65		$	211		$	195
Interest cost on projected
benefit obligation	880			860			2,639			2,579
Expected return on plan assets	(1,094		)	(1,131		)	(3,283		)	(3,394		)
Net amortization and deferral	394			731			1,183			2,195
Net periodic pension cost	$	250		$	525		$	750		$	1,575