Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2011

Benefit Plans [Abstract]

Components of net periodic benefit cost

	Pension Benefits
	Quarter ended						Six months ended
	June 30,						June 30,
	2011			2010			2011			2010
Components of Net Periodic Pension Cost
Service Cost	$	1,531		$	1,480		$	3,062		$	2,959
Interest Cost		2,860			2,800			5,720			5,600
Expected return on assets		(3,328	)		(3,015	)		(6,656	)		(6,029	)
Amortization of unrecognized prior service costs		98			98			196			197
Cumulative net loss		1,780			1,427			3,560			2,854
Net periodic pension cost	$	2,941		$	2,790		$	5,882		$	5,581

	Postretirement Benefits
	Quarter ended				Six months ended
	June 30,				June 30,
	2011		2010		2011		2010
Components of Net Periodic Postretirement Cost
Service Cost	$	14	$	15	$	28	$	30
Interest Cost		221		240		442		480
Amortization of unrecognized prior service costs		—		—		—		—
Cumulative net loss		28		4		56		8
Net periodic postretirement cost	$	263	$	259	$	526	$	518