Employee Benefit Plans Employee Benefit Plans and Components of Net Periodic Postretirement Benefit Cost (Benefit) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Estimated Cost Reduction of Net Periodic Pension and Post Retirement Benefit Costs	$ 1,200,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements		$ 3,915,000	$ 0	$ 0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		2,923,000	0	0
Pension Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		549,000	453,000	699,000
Interest cost		6,938,000	6,885,000	6,327,000
Expected return on assets		(9,395,000)	(8,381,000)	(9,278,000)
Amortization of prior service cost		244,000	282,000	322,000
Amortization of actuarial loss (gain)		4,018,000	1,717,000	1,942,000
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements		3,915,000	0	0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments		2,923,000	0	0
Net periodic pension plans cost		9,192,000	956,000	12,000
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		83,000	56,000	153,000
Interest cost		79,000	76,000	148,000
Amortization of actuarial loss (gain)		(197,000)	(336,000)	(23,000)
Net periodic pension plans cost		$ (35,000)	$ (204,000)	$ 278,000