Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Reconciliation of income taxes to the expected statutory federal corporate income tax rates
Income tax expense (benefit)	$ 12	$ 2,104	$ 4,328	$ 3,575
Federal
Reconciliation of income taxes to the expected statutory federal corporate income tax rates
Net operating loss carryforwards					$ 619,500
California
Reconciliation of income taxes to the expected statutory federal corporate income tax rates
Operating loss carryforwards expired					$ 431,600