Income Taxes, AMT Credits Carryforwards (Details)	9 Months Ended
	Sep. 30, 2018 USD ($)
Income Taxes [Abstract]
AMT Credits carryforwards	$ 21,600,000
Alternative Minimum Tax (AMT) Credit Carryforward [Member]
Alternative Minimum Tax ("AMT") Credit Carryforwards Projected to be Claimed as Refundable for Each Tax Year [Abstract]
AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year	20,092,000	[1],[2]
Alternative Minimum Tax (AMT) Credit Carryforward [Member] | Tax Year 2018 [Member]
Alternative Minimum Tax ("AMT") Credit Carryforwards Projected to be Claimed as Refundable for Each Tax Year [Abstract]
Declining balance of the AMT Credit carryforward amount(s) available for each tax year	$ 20,092,000	[1],[2]
% of AMT Credit carryforward amount(s) available to be claimed as refundable for each tax year	50.00%
AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year	$ 10,046,000	[1],[2]
Alternative Minimum Tax (AMT) Credit Carryforward [Member] | Tax Year 2019 [Member]
Alternative Minimum Tax ("AMT") Credit Carryforwards Projected to be Claimed as Refundable for Each Tax Year [Abstract]
Declining balance of the AMT Credit carryforward amount(s) available for each tax year	$ 10,046,000	[1],[2]
% of AMT Credit carryforward amount(s) available to be claimed as refundable for each tax year	50.00%
AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year	$ 5,023,000	[1],[2]
Alternative Minimum Tax (AMT) Credit Carryforward [Member] | Tax Year 2020 [Member]
Alternative Minimum Tax ("AMT") Credit Carryforwards Projected to be Claimed as Refundable for Each Tax Year [Abstract]
Declining balance of the AMT Credit carryforward amount(s) available for each tax year	$ 5,023,000	[1],[2]
% of AMT Credit carryforward amount(s) available to be claimed as refundable for each tax year	50.00%
AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year	$ 2,511,500	[1],[2]
Alternative Minimum Tax (AMT) Credit Carryforward [Member] | Tax Year 2021 [Member]
Alternative Minimum Tax ("AMT") Credit Carryforwards Projected to be Claimed as Refundable for Each Tax Year [Abstract]
Declining balance of the AMT Credit carryforward amount(s) available for each tax year	$ 2,511,500	[1],[2]
% of AMT Credit carryforward amount(s) available to be claimed as refundable for each tax year	100.00%
AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year	$ 2,511,500	[1],[2]

[1] Assumes no regular federal income tax liability in tax years presented above which would reduce any AMT Credit carryforward amount(s) ultimately refunded.

[2] The declining balance of the AMT Credit carryforward amount(s) available for each tax year and the AMT Credit carryforward amount(s) projected to be claimed as refundable for each tax year are net of certain estimated adjustments from the previously disclosed AMT Credit carryforward amounts.