Taxes (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Stock options and other equity based compensation, tax expense (benefit)					$ 6,700	$ 1,600	$ 1,500
Operating loss carryforwards					3,000,000
Alternative minimum tax credit carryforwards	$ 127,169				120,994	127,169
Increase (decrease) in valuation allowance	807,200	$ 15,800	$ 18,300	$ 23,800	865,100	226,900	8,700
Interest and penalties accrued related to unrecognized tax benefits	$ 1,500				1,700	$ 1,500
Reductions as a result of lapses in the statute of limitations					$ 0		$ 1,248