Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Cash and cash equivalents	$ 546,675	$ 339,629
Current assets	1,312,025	942,927
Total assets	6,497,082	6,515,628
Current liabilities	1,311,361	1,070,804
Liabilities	$ 3,915,311	$ 3,699,182
Preferred Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	49,889,000	49,889,000
Preferred Stock, Shares Issued	0
Preferred Stock, Shares Outstanding	0	0
Treasury Stock, Shares	17,627,000	16,008,000
Class A Common Stock
Common Stock, Par or Stated Value Per Share	$ 0.004	$ 0.004
Common Stock, Shares Authorized	700,000,000	700,000,000
Common Stock, Shares, Issued	136,702,000	135,583,000
Common Stock, Shares, Outstanding	119,075,000	119,575,000
Class B Common Stock
Common Stock, Par or Stated Value Per Share	$ 0.004	$ 0.004
Common Stock, Shares Authorized	175,000,000	175,000,000
Common Stock, Shares, Issued	90,813,000	90,831,000
Common Stock, Shares, Outstanding	90,813,000	90,831,000