Employee Benefit Plans Amounts Recognized Accumlated Other Comprehensive Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive (loss) income as of January 1, 2015	$ (29,899)	$ (26,216)
Amortization of gain (loss)	4,200	1,015
Net (loss) gain arising during the year	(8,620)	(4,698)	$ 9,513
Accumulated other comprehensive (loss) income as of December 31, 2015	(34,319)	(29,899)	(26,216)
Defined Benefit Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive (loss) income as of January 1, 2015	(30,481)	(27,102)
Amortization of gain (loss)	4,297	1,075
Net (loss) gain arising during the year	(9,074)	(4,454)
Accumulated other comprehensive (loss) income as of December 31, 2015	(35,258)	(30,481)	(27,102)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive (loss) income as of January 1, 2015	582	886
Amortization of gain (loss)	(97)	(60)
Net (loss) gain arising during the year	454	(244)
Accumulated other comprehensive (loss) income as of December 31, 2015	$ 939	$ 582	$ 886