Summary of Significant Accounting Policies - Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Accounting Policies [Abstract]
Effective Tax Rate	28.50%	0.00%	27.90%	25.10%
Expense related to change in enacted tax law	$ 12,000		$ 12,000
Provision (benefit) for income taxes	110,416	$ 9,683	125,056	$ 19,370
Net income before provision for income taxes	$ 386,938	$ 2,570	$ 448,209	$ 77,149