Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Accounts receivable, allowance	$ 0	$ 0
Common stock, par value	$ 0.00000625	$ 0.00000625
Common stock, shares authorized	2,020,517,000	2,020,517,000
Common stock, shares outstanding	889,328,000	903,617,000
Common Class A [Member]
Common stock, shares outstanding	772,573,000	769,533,000
Common Class B [Member]
Common stock, shares outstanding	96,238,000	113,567,000
Common Class C [Member]
Common stock, shares outstanding	20,517,000	20,517,000