Employee Benefits Plans (Details 7) - Level 3 - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Summary of changes in fair value of the pension plans' level 3 assets
Fair value of plan assets at January 1	$ 100,631	$ 89,727
Return on plan assets:
Relating to assets still held at the reporting date	1,548	5,399
Relating to assets sold during the period	703	226
Purchases, sales, settlements and expenses	2	5,279
Fair value of plan assets at December 31	$ 102,884	$ 100,631