Commitments and Contingencies - Narrative (Details) (USD $)	1 Months Ended	12 Months Ended
	Jul. 31, 2005 extension	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Sale Leaseback Transaction [Abstract]
Gain recognized on sale-lease back transaction		$ 56,000	$ 56,000
Office building
Sale Leaseback Transaction [Abstract]
Proceeds from the sale-leaseback transaction	2,100,000
Sale-leaseback term	10 years
Options to extend term of the lease for additional five years	2
Maximum extension term of each option to extend	5 years
Deferred gain on sale-leaseback transaction	562,000
Gain recognized on sale-lease back transaction		56,000
Rent expense		172,620	172,620	170,219
Vehicles
Operating Leases, Rent Expense, Net [Abstract]
Rent expense		2,800,000	4,600,000	3,600,000
Office building
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		9 years
Other facilities | Minimum
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		1 year
Other facilities | Maximum
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		5 years
Land
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		20 years
Prepayments of future operating lease payments		$ 250,000