Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Commitments and Contingencies [Line Items]
Net rental expense	$ 2,100,000	$ 2,200,000	$ 2,200,000
Future Obligations for Minimum Rentals Under Non-Cancelable Operating Lease Commitments
2015	2,028,000
2016	1,877,000
2017	1,467,000
2018	1,270,000
2019	1,215,000
Thereafter	9,658,000
Total lease commitments	$ 17,515,000
Minimum [Member]
Commitments and Contingencies [Line Items]
Lease Term, Facilities	5 years
Maximum [Member]
Commitments and Contingencies [Line Items]
Lease Term, Facilities	10 years
Lease Term, Equipment	5 years