Lease Commitments (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Lease Commitments
Rent paid for offices leased from unrelated third parties	$ 1,900,000	$ 1,300,000
Future minimum rentals to be paid under non-cancellable operating leases
2013	1,033,000
2014	705,000
2015	556,000
2016	468,000
2017	290,000
2018	281,000
2019	286,000
2020	287,000
2021	290,000
2022	47,000
Total	$ 4,243,000