Income Taxes (Narrative) (Details) - USD ($)		12 Months Ended
	Jul. 23, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Net deferred tax assets		$ 141,716,000	$ 146,433,000
Valuation allowance		0	1,300,000
Increase (decrease) in valuation allowance		(1,300,000)	(146,743,000)	$ (34,578,000)
Amount in retained earnings for additions to the tax bad debt reserve for which no federal tax provision has been made		5,000,000
Unrecognized tax benefits		0	0
Deferred tax assets related to NOL carryforwards		133,524,000	137,412,000
Reduction in deferred income tax asset	$ 2,300,000
Granite Corp. [Member]
Income Tax [Line Items]
Increase (decrease) in valuation allowance			28,300,000
Deferred tax assets related to NOL carryforwards			2,900,000
Federal Tax Authority [Member]
Income Tax [Line Items]
Operating loss carryforwards		$ 352,000,000	355,900,000
Federal Tax Authority [Member] | Minimum [Member]
Income Tax [Line Items]
Remaining carryforward periods		14 years
Federal Tax Authority [Member] | Maximum [Member]
Income Tax [Line Items]
Remaining carryforward periods		18 years
State Jurisdiction [Member]
Income Tax [Line Items]
Operating loss carryforwards		$ 368,700,000	$ 371,800,000
Increase (decrease) in valuation allowance		$ 142,500,000
State Jurisdiction [Member] | Minimum [Member]
Income Tax [Line Items]
Remaining carryforward periods		13 years
State Jurisdiction [Member] | Maximum [Member]
Income Tax [Line Items]
Remaining carryforward periods		9 years