Leases (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease Practical Expedient Transition Approach	true
Lease, Practical Expedients, Package [true false]	true
Lease Practical Expedient Lease Capitalization	true
Lease Practical Expedient Separate Lease Non Lease Components	false
Lease Practical Expedient Land Easement	true
Right of use assets	$ 32,312	$ 46,647
Lease liability	32,961	46,875
Impact on retained earnings	1,256,808	2,050,165	$ 2,750,326	$ 2,938,773
Retained Earnings (Accumulated Deficit)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on retained earnings	(946,100)	$ (104,775)	$ 650,842	$ 1,423,154
Accounting Standards Update 2016-02 | Cumulative effect period of adoption adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right of use assets	42,800
Lease liability	42,800
Accounting Standards Update 2016-02 | Cumulative effect period of adoption adjustment | Retained Earnings (Accumulated Deficit)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact on retained earnings	$ 0