Pension and Other Postretirement Benefits - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Requisite service period			3 years
Contributions by employer	$ 44,002	$ 10,002	$ 81,633	$ 31,536
Estimated future contributions in remainder of 2016			$ 2