Employee Benefit Plans (Details 2) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Pension Benefits
Benefit costs
Service cost (benefit)		$ (50,000)		$ 1,488,000
Interest cost	2,055,000	2,557,000	6,166,000	7,493,000
Expected asset return	(2,934,000)	(2,890,000)	(8,804,000)	(8,601,000)
Amortization of loss	148,000	131,000	444,000	373,000
Net periodic benefit cost	(731,000)	(252,000)	(2,194,000)	753,000
Expected company contribution					12,100,000
Company contribution			9,400,000
Other Postretirement Benefits
Benefit costs
Service cost (benefit)	277,000	221,000	832,000	724,000
Interest cost	516,000	576,000	1,548,000	1,772,000
Amortization of loss	74,000	7,000	223,000	88,000
Net periodic benefit cost	$ 867,000	$ 804,000	$ 2,603,000	$ 2,584,000