Unaudited Condensed Consolidated Statements of Cash Flows - Supplemental - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Supplemental disclosures:
Cash and cash equivalents	$ 154,822	$ 156,540
Restricted cash (Note 1)	108	105
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	154,930	156,645
Cash paid for income taxes, net of refunds	4,152	3,863
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	517	617
Investment purchases in accounts payable, net	$ 0	$ 13,451