Short-Term Borrowings and Other Debt (Details) (USD $)	3 Months Ended					3 Months Ended
	Mar. 31, 2013 letters_of_credit		Mar. 31, 2012	Dec. 31, 2010	Dec. 31, 2012	Mar. 31, 2013 Minimum	Mar. 31, 2013 Maximum	Mar. 31, 2013 Insurance Note [Member]	Jan. 31, 2013 Insurance Note [Member]	Mar. 31, 2013 Letter of Credit, San Francisco Office, Expires May 2013 Letter of Credit	Mar. 31, 2013 Letter of Credit, Expires September 2013 Letter of Credit	Mar. 31, 2013 Letter of Credit, Expires December 2013 Letter of Credit	Mar. 31, 2013 Letter of Credit, Expires February 2014 Letter of Credit	Mar. 31, 2013 Letter of Credit, Expires July 2013 Letter of Credit
Components of short-term borrowings and other debt
Notes payable	$ 1,799,000				$ 206,000			$ 1,600,000	$ 2,000,000
Capital lease obligations	3,580,000				3,926,000
Short-term borrowings and other debt	5,379,000				4,132,000
Interest rate								2.22%
Monthly payment								200,000
Capital leases entered into				6,300,000
Capital leases, term						48 months	60 months
Capital leases, interest rate						0.60%	6.14%
Capital lease interest expense	100,000		100,000
Number of letters of credit, in letters of credit	5
Letter of credit, borrowing capacity										82,000	1,200,000.0	6,700,000.0	1,000,000.0	1,800,000.0
Future minimum lease payments for capital lease obligations
2013	1,158,000
2014	1,402,000
2015	1,051,000
2016	194,000
2017	0
Thereafter	0
Subtotal	3,805,000
Less: Amount representing interest	(225,000)	[1]
Total	3,580,000
Repayments on long-term and short-term borrowings
2013	1,808,000
2014	46,000
2015	0
2016	0
2017	0
Thereafter	0
Subtotal	1,854,000
Less: Amount representing interest	(55,000)	[1]
Notes payable	$ 1,799,000				$ 206,000			$ 1,600,000	$ 2,000,000

[1] Amount necessary to reduce net minimum lease payments to present value calculated at the Company's implicit rate at lease inception.