Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Operating activities
Net income	$ 76,388	$ 88,132
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58,374	53,781
Amortization of operating lease assets	42,961	38,105
Deferred income tax provision	27,343	1,772
Impairment, closure costs, and asset disposals	8,805	4,085
Provision for credit losses	(90)	206
Stock-based compensation expense	17,395	19,154
Other	707	(1,269)
Changes in operating assets and liabilities:
Accounts receivable	25,967	15,946
Inventory	2,734	2,781
Prepaid expenses and other current assets	(4,158)	(3,712)
Other assets	(5,133)	242
Accounts payable	20,245	(4,256)
Accrued payroll and benefits	5,839	5,853
Accrued liabilities	(9,389)	(4,773)
Unearned revenue	(15,924)	(13,386)
Income tax payable/receivable	(29,179)	16,054
Operating lease liabilities	(40,918)	(36,492)
Other long-term liabilities	104	358
Net cash provided by operating activities	182,071	182,581
Investing activities
Purchases of leasehold improvements, property and equipment	(77,653)	(64,226)
Purchases of investments	(80,746)	(89,111)
Maturities of investments	99,037	60,000
Net cash used in investing activities	(59,362)	(93,337)
Financing activities
Acquisition of treasury stock	(54,401)	(52,886)
Tax withholding on stock-based compensation awards	(47,630)	(10,368)
Stock plan transactions and other financing activities	(69)	(277)
Net cash used in financing activities	(102,100)	(63,531)
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(819)	178
Net change in cash, cash equivalents, and restricted cash	19,790	25,891
Cash, cash equivalents and restricted cash at beginning of period	508,481	280,152
Cash, cash equivalents and restricted cash at end of period	528,271	306,043
Supplemental disclosures of cash flow information
Income taxes paid (refunded)	(14)
Income taxes paid (refunded)		7,361
Purchases of leasehold improvements, property, and equipment accrued in accounts payable and accrued liabilities	33,757	22,386
Acquisition of treasury stock accrued in accounts payable and accrued liabilities	$ 0	$ 1,600