Income Taxes Domestic Tax Components (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Federal
Current	$ 723	$ (3,527)	$ (405)
Deferred	(2,054)	33,031	(5,658)
Investment tax credits	(196)	(232)	(273)
State
Current	10	(90)	18
Deferred	(6,130)	855	(3,954)
Income Tax (Benefit) Expense	$ (7,647)	$ 30,037	$ (10,272)

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

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The amount deducted from an entities' taxes, reflecting a percentage of an amount invested in certain assets spread over the useful life of those assets; includes deferred investment tax credits.

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