Defined Benefit Plans - Defined Benefit Plans Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	$ 0	$ 0	$ 0	$ 0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	0	$ 2,750	0	$ 2,750
Defined Benefit Plan, Contributions by Employer	$ 600		1,100
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year			$ 2,000