Income Taxes (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jul. 31, 2013	Dec. 31, 1987
Income Taxes
Period for which prior cumulative losses considered in assessing the realization of deferred tax assets	2 years
Tax bad debt reserve				$ 3,000,000
Deferred tax liability not recorded on tax bad debt reserve balance	1,000,000	1,000,000
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Balance at beginning of year	488,000	431,000	0
Additions based on tax positions related to the current year		86,000
Reductions for tax positions of prior years	(13,000)	(29,000)
Balance at end of year	475,000	488,000	0
Unrecognized tax benefits if recognized would favorably affect income tax provision in future	475,000
Interest accrued during the period related to unrecognized tax benefits	3,000	3,000
General Business Tax Credit Carryforward
Income taxes
Tax credit carryforward	938,000
Alternative Minimum Tax Credit Carryforward
Income taxes
Tax credit carryforward	113,000
Federal
Income taxes
Net operating loss carryforwards	14,800,000
California
Income taxes
Net operating loss carryforwards	$ 32,100,000