CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Revenue	$ 4,713,500	$ 3,298,177	$ 2,214,253
Cost of Revenue [Abstract]
Cost of revenue	136,385	94,114	62,393
Total cost of revenue	2,823,815	1,994,477	1,374,947
Gross profit	1,889,685	1,303,700	839,306
Operating expenses:
Product development	670,606	497,479	321,888
Sales and marketing	624,832	411,151	253,170
General and administrative	436,250	339,245	250,553
Transaction and loan losses	126,959	88,077	67,018
Total operating expenses	1,863,128	1,340,314	893,512
Operating income (loss)	26,557	(36,614)	(54,206)
Gain on sale of asset group	(373,445)	0	0
Interest expense, net	21,516	17,982	10,053
Other expense (income), net	273	(18,469)	(1,595)
Income (loss) before income tax	378,213	(36,127)	(62,664)
Provision for income taxes	2,767	2,326	149
Net income (loss)	$ 375,446	$ (38,453)	$ (62,813)
Net income (loss) per share:
Basic (in USD per share)	$ 0.88	$ (0.09)	$ (0.17)
Diluted (in USD per share)	$ 0.81	$ (0.09)	$ (0.17)
Weighted-average shares used to compute net income (loss) per share:
Basic (in shares)	424,999	405,731	379,344
Diluted (in shares)	466,076	405,731	379,344
Transaction-based revenue
Revenue:
Revenue	$ 3,081,074	$ 2,471,451	$ 1,920,174
Cost of Revenue [Abstract]
Cost of revenue	1,937,971	1,558,562	1,230,290
Subscription and services-based revenue
Revenue:
Revenue	883,922	499,010	185,485
Revenue	1,031,456	591,706	252,664
Cost of Revenue [Abstract]
Cost of revenue	234,270	169,884	75,720
Hardware revenue
Revenue:
Revenue	84,505	68,503	41,415
Bitcoin revenue
Revenue:
Revenue	516,465	166,517	0
Cost of Revenue [Abstract]
Cost of revenue	508,239	164,827	0
Acquired technology
Cost of Revenue [Abstract]
Amortization of acquired technology	6,950	7,090	6,544
Acquired customers
Operating expenses:
Amortization of acquired customer assets	$ 4,481	$ 4,362	$ 883