Consolidated Statements of Cash Flows (Unaudited) - USD ($)	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Operating activities:
Net income	$ 3,024,000	$ 7,959,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of property, equipment and software	16,758,000	12,927,000
Amortization of intangible assets	12,774,000	9,740,000
Amortization of deferred financing costs	282,000	1,042,000
Stock-based compensation expense	14,208,000	9,380,000
Deferred income taxes	(3,900,000)	1,265,000
Change in fair value of contingent consideration		500,000
Release of estimated liability for appeals	(8,436,000)
Changes in operating assets and liabilities:
Accounts receivable	(3,654,000)	(9,039,000)
Prepaid expenses	63,000	149,000
Other current assets	570,000	526,000
Other assets	(29,000)	149,000
Income taxes receivable / (payable)	(5,324,000)	(6,180,000)
Accounts payable, accrued expenses and other liabilities	(2,546,000)	(8,196,000)
Estimated liability for appeals	(99,000)	518,000
Net cash provided by operating activities	23,691,000	20,740,000
Investing activities:
Acquisition of a business, net of cash acquired		(171,174,000)
Purchases of property and equipment	(2,455,000)	(8,881,000)
Investment in capitalized software	(10,173,000)	(6,626,000)
Net cash used in investing activities	(12,628,000)	(186,681,000)
Financing activities:
Proceeds from exercise of stock options	2,390,000	1,986,000
Payments of tax withholdings on behalf of employees for net-share settlement for stock-based compensation	(2,684,000)	(2,874,000)
Payments on capital lease obligations		(5,000)
Proceeds from credit facility		42,204,000
Purchases of treasury stock	(5,955,000)
Net cash (used in)/provided by financing activities	(6,249,000)	41,311,000
Net increase (decrease) in cash and cash equivalents	4,814,000	(124,630,000)
Cash and Cash Equivalents
Cash and cash equivalents at beginning of year	83,313,000	175,999,000
Cash and cash equivalents at end of period	88,127,000	51,369,000
Supplemental disclosure of cash flow information:
Cash paid for income taxes	11,472,000	10,656,000
Cash paid for interest	4,916,000	3,451,000
Supplemental disclosure of non-cash activities:
Change in balance of accrued property and equipment purchases	$ 1,082,000	$ (1,313,000)