CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities:
Net income	$ 133,153	$ 148,417
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	52,235	38,413
Amortization of deferred commissions costs	29,662	25,550
Amortization of debt issuance costs	508	438
Realized loss on investments	541	0
Non-cash lease expense	12,400	10,859
Stock-based compensation expense	24,053	25,845
Deferred income taxes, net	3,569	6,359
Credit loss expense	15,688	5,224
Foreign currency, net	(789)	0
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(37,364)	(10,898)
Income taxes payable	12,328	(5,577)
Prepaid expenses and other current assets	4,371	1,751
Deferred commissions	(32,122)	(33,397)
Other assets	(6,757)	236
Accounts payable and other liabilities	37,793	22,691
Lease liabilities	(14,126)	(12,977)
Deferred revenue	13,503	10,633
Net cash provided by operating activities	248,646	233,567
Investing activities:
Proceeds from sale and settlement of investments	10,259	0
Purchases of property and equipment and other assets	(12,782)	(14,387)
Cash paid for acquisitions, net of cash acquired	184,502	13,721
Net cash used in investing activities	(187,025)	(28,108)
Financing activities:
Proceeds from long-term debt	745,000	0
Repurchase of restricted stock to satisfy tax withholding obligations	(33,653)	(24,225)
Proceeds from equity offering, net of transaction costs	1,690,148	0
Proceeds from exercise of stock options and employee stock purchase plan	16,513	16,695
Other financing activities	(1,650)	(123)
Net cash provided by (used in) financing activities	2,416,358	(7,653)
Effect of foreign currency exchange rates on cash and cash equivalents	(305)	(410)
Net increase in cash, cash equivalents and restricted cash	2,477,674	197,396
Cash, cash equivalents and restricted cash at the beginning of period	1,070,731	1,100,416
Cash, cash equivalents and restricted cash at the end of period	3,548,405	1,297,812
Supplemental cash flow disclosures:
Interest paid	5,194	1,007
Income taxes paid	6,558	28,484
Supplemental non-cash investing and financing activities:
Consideration owed for acquisitions	$ 0	$ 1,650