Shared-based Compensation (Summary of Restricted Stock Units and Performance Stock Units Activity) (Details) - Restricted Stock Units (RSUs) and Performance Stock Units (PSUs) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of Shares
Outstanding, beginning balance (in shares)	11,019,472	4,724,673	1,685,060
Granted (in shares)	6,687,695	5,609,561	4,168,477
LTCI modification (in shares)		2,989,965
Forfeited (in shares)	(918,425)	(753,653)	(552,981)
Vested (in shares)	(3,872,453)	(1,551,074)	(575,883)
Outstanding, ending balance (in shares)	12,916,289	11,019,472	4,724,673
Vested and expected to vest, end of period (in shares)	12,098,438
Aggregate Intrinsic Value
Outstanding, end of period	$ 60,577,395
Vested and expected to vest	$ 56,741,674