Leases (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Operating Leased Assets [Line Items]
2012	$ 4,751,000
2013	3,890,000
2014	2,268,000
2015	1,436,000
2016	1,058,000
Thereafter	2,976,000
Operating Leases, Future Minimum Payments Due	16,379,000
Operating Leases, Rent Expense, Net	5,600,000	3,600,000	2,900,000
Corporate Office [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Operating Leases, Future Monthly Lease Payments	35,694
Corporate Office [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Operating Leases, Future Monthly Lease Payments	42,635
Other Noncancelable [Member]
Operating Leased Assets [Line Items]
Operating Lease, Number of Leased Locations	54
Other Noncancelable [Member] | Minimum [Member]
Operating Leased Assets [Line Items]
Operating Leases, Future Monthly Lease Payments	380
Other Noncancelable [Member] | Maximum [Member]
Operating Leased Assets [Line Items]
Operating Leases, Future Monthly Lease Payments	$ 36,000