Revenue (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Short-term contract asset	$ 46,600,000	$ 37,300,000
Long-term contract asset	40,500,000	41,700,000
Current portion of deferred revenues	1,708,058,000	1,510,216,000
Long-term portion of deferred revenues	329,535,000	392,360,000
Deferred revenue recognized	1,470,000,000	1,330,000,000
Asset impairment charges related to contracts	$ 0	$ 0