Income Taxes Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Valuation Allowance [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Foreign	$ 39,850	$ 25,903
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	219,872	143,122
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	305	53
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	252	53
Deferred Tax Assets, Valuation Allowance, Noncurrent	60,488	42,983
Valuation Allowance, Deferred Tax Asset, Change in Amount	10,591	9,420
Current Federal Tax Expense (Benefit)	(103,562)	19,726	$ 18,388
Current State and Local Tax Expense (Benefit)	(8,699)	(5,657)	2,724
Current Foreign Tax Expense (Benefit)	1,966	964	1,411
Current Income Tax Expense (Benefit)	(110,295)	15,033	22,523
Deferred Federal Income Tax Expense (Benefit)	124,766	(181,859)	(12,581)
Deferred State and Local Income Tax Expense (Benefit)	(4,461)	41,387	5,262
Deferred Income Tax Expense (Benefit)	120,305	(140,472)	(7,319)
Income Tax Expense (Benefit)	10,010	$ (125,439)	$ 15,204
Charitable Contributions [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Noncurrent	5,051
Alternative Minimum tax credit [Member]
Valuation Allowance [Line Items]
Deferred Tax Assets, Valuation Allowance, Noncurrent	$ 166,798