Pension Plans (Details 6) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	$ 16,212	$ 17,281
Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	15,152	16,400
Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	1,060	881
Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Short-term Investments [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	607	753
Short-term Investments [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Short-term Investments [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	607	753
Short-term Investments [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Corporate stocks - common [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	3,831	4,092
Corporate stocks - common [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	3,831	4,092
Corporate stocks - common [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Corporate stocks - common [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Mutual funds - equity [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	5,775	6,084
Mutual funds - equity [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	5,775	6,084
Mutual funds - equity [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Mutual funds - equity [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Exchange traded funds [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	4,938	5,698
Exchange traded funds [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	4,938	5,698
Exchange traded funds [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Exchange traded funds [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Government [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	608	526
Government [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	608	526
Government [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Government [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Asset backed [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	453	128
Asset backed [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	0	0
Asset backed [Member] | Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	453	128
Asset backed [Member] | Level 3 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	$ 0	$ 0