CONSOLIDATED STATEMENTS OF CASH FLOWS (unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Statement of Cash Flows [Abstract]
Net Income (Loss) Available to Common Stockholders, Basic	$ 9,390	$ 19,985
OPERATING ACTIVITIES
Net income	9,390	19,985
Adjustments to reconcile net income to net cash provided by operating activities:
Credit loss expense	12,186	10,527
Depreciation and amortization	21,364	20,213
Stock-based compensation	7,060	6,026
Accretion of debt discount	498	621
Deferred income taxes	4,100	1,980
Change in fair value of acquisition-related contingent consideration	1,850	(1,810)
Other non-cash items	909	(398)
Changes in operating assets and liabilities:
Healthcare and other accounts receivable	(5,670)	(19,643)
Inventory	(1,191)	1,286
Prepaid expenses and other assets	(520)	(3,366)
Accounts payable	(2,707)	3,837
Accrued and other liabilities	22,276	(3,128)
Net cash provided by operating activities	69,545	36,130
INVESTING ACTIVITIES
Acquisition of business, net of cash acquired	0	(44,766)
Purchases of property and equipment and investment in internally developed software	(17,110)	(16,092)
Net cash used in investing activities	(17,110)	(60,858)
FINANCING ACTIVITIES
Proceeds related to the exercising of stock options and employee stock purchase plan	2,508	4,729
Payments of tax withholdings related to vesting of share-based awards	(1,655)	(4,955)
Principal payments on long-term debt	(197,825)	(2,563)
Repayments of Lines of Credit	70,000	0
Proceeds from borrowings on revolving credit facility	232,000	0
Payments of debt issuance costs	(1,684)	0
Principal payments on finance lease obligations	(332)	(1,659)
Net cash provided by/(used in) financing activities	(36,988)	(4,448)
Effect of exchange rate changes on cash	(58)	(1)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	15,389	(29,177)
Cash and cash equivalents - beginning of period	68,614	80,889
Cash and cash equivalents - end of period	84,003	51,712
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Non-cash purchases of property and equipment	4,761	1,645
Non-cash Fair Value of Equity Issued for Acquisition of Business	0	2,142
Non-cash Fair Value Of Customer Lists Acquired	5,470	0
Cash paid for interest	3,065	4,327
Cash paid for taxes	$ 636	$ 312