Organization and Summary of Significant Accounting Policies - Adjustments to Opening Balance Sheet (Details) - USD ($) $ in Thousands	Jan. 01, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment to retained earnings		$ (895,153)	$ (869,813)	$ (559,590)	$ (543,495)	$ (507,647)	$ (488,927)	$ (480,539)	$ (467,324)
Impact of Adoption of Topic 326 on opening balance sheet
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment, income taxes	$ 200
Cumulative Effect, Period of Adoption, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment to retained earnings					$ 640
Cumulative Effect, Period of Adoption, Adjustment | Impact of Adoption of Topic 326 on opening balance sheet
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment to retained earnings	$ 600