Segment Information (Reconciliation Of Total Operating (Loss) Income To Total Adjusted OIBDA) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Operating income		$ 55,748	$ 17,110	$ 109,041	$ 10,251
Depreciation and amortization	[1]	10,768	5,838	21,668	12,258
Stock-based compensation		6,989	11,664	20,054	24,492
Other adjustments
Total Adjusted OIBDA		73,505	$ 34,612	150,763	$ 47,001
Global Headquarters [Member]
Segment Reporting Information [Line Items]
Depreciation and amortization		$ 2,266		$ 4,532

[1] Depreciation and amortization for the three and six months ended June 30, 2020 includes $2,266 and $4,532, respectively, of amortization related to the right-of-use asset for the Company’s new global headquarters lease, which commenced on July 1, 2019 and is accounted for as a finance lease.