Income Taxes Reconciliation of Tax Expense (Benefit) and Other (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal statutory tax benefit		$ (48,519,000)	$ 136,873,000	$ (120,335,000)
Federal tax reform changes - 2017 Tax Act		0	0	(63,675,000)
State tax benefit (net of federal benefit)		260,000	2,771,000	(3,286,000)
Change in valuation allowance		(13,000)	105,000	(2,727,000)
Employee share-based compensation		3,346,000	2,508,000	8,190,000
Other		883,000	1,113,000	(1,137,000)
Income tax expense (benefit)		(44,043,000)	143,370,000	(182,970,000)
Proceeds from income tax refunds	$ 7,700,000
Proceeds expected from income tax refunds	3,800,000	3,800,000
Unrecognized tax benefits [Roll Forward]
Unrecognized tax benefits	$ 446,000	$ 446,000	$ 446,000	$ 446,000