Summary Of Significant Accounting Policies Consolidated Statement of Cash Flows - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents		$ 779,901	$ 798,329
Restricted cash	[1]	28,541	18,567
Total cash, cash equivalents, and restricted cash		$ 808,442	$ 816,896	$ 1,019,426	$ 153,614

[1] Restricted cash balances are included in "prepaid expenses and other assets" on our consolidated balance sheets.