Employee Benefit Plans (Details 6) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	$ 17,281	$ 16,731
Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	16,400	15,884
Level 2 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	881	847
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	753	574
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	753	574
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	4,092	4,054
Corporate stocks - common [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	4,092	4,054
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	6,084	5,918
Mutual funds - equity [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	6,084	5,918
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	5,698	5,458
Exchange traded funds [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	5,698	5,458
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	526	454
Government [Member] | Level 1 [Member]
Company's pension plans' asset valuation in the fair value hierarchy levels
Plan assets at fair value	526	454
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	128	273
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	128	273
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