Short-Term Borrowings and Other Debt (Details) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2012 letters_of_credit		Dec. 31, 2011	Dec. 31, 2010
Components of short-term borrowings and other debt
Notes payable		$ 206,000		$ 370,000
Capital lease obligations		3,926,000		5,280,000
Short-term borrowings and other debt		4,132,000		5,650,000
Capital leases entered into	6,300,000
Capital lease interest expense		200,000		200,000	0
Number of letters of credit, in letters of credit		4
Future minimum lease payments for capital lease obligations
2013		1,541,000
2014		1,402,000
2015		1,051,000
2016		194,000
2017		0
Thereafter		0
Subtotal		4,188,000
Less: Amount representing interest		(262,000)	[1]
Total		3,926,000
Repayments on long-term and short-term borrowings
2013		183,000
2014		46,000
2015		0
2016		0
2017		0
Thereafter		0
Subtotal		229,000
Less: Amount representing interest		(23,000)	[1]
Notes payable		206,000		370,000
Minimum
Components of short-term borrowings and other debt
Capital leases, term		48 months
Capital leases, interest rate		0.60%
Maximum
Components of short-term borrowings and other debt
Capital leases, term		60 months
Capital leases, interest rate		6.14%
Letter of Credit, San Francisco Office, Expires May 2013 [Member] | Letter of Credit [Member]
Components of short-term borrowings and other debt
Letter of credit, borrowing capacity		82,000
Letter of Credit, Expires September 2013 [Member] | Letter of Credit [Member]
Components of short-term borrowings and other debt
Letter of credit, borrowing capacity		1,200,000.0
Letter of Credit, Expires December 2013 [Member] | Letter of Credit [Member]
Components of short-term borrowings and other debt
Letter of credit, borrowing capacity		6,700,000.0
Letter of Credit, Expires February 2013 [Member] | Letter of Credit [Member]
Components of short-term borrowings and other debt
Letter of credit, borrowing capacity		$ 1,000,000.0

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