Income Taxes (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Operating loss carryforwards	$ 520,000,000
Income tax expense (benefit)	0
Penalties and interest expense	0
Liability for uncertainty in income taxes, current	0	$ 0
Outstanding refundable tax credits due	0
Other nonoperating income	$ 121,000	$ 0	$ 83,000