Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019	Sep. 30, 2019
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member
Reduction in retained earnings	$ (2,348,728)		$ (2,141,302)	$ (2,118,860)
Cumulative Effect, Period of Adoption, Adjustment
Reduction in retained earnings		$ 700