Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 88,238	$ 85,271
Accounts receivable (less allowance for doubtful accounts of $7,394 and $5,742 as of September 30, 2019 and December 31, 2018, respectively)	273,021	242,814
Prepaid expenses and other current assets	60,328	50,136
Income tax receivable	2,673	25,299
Total current assets	424,260	403,520
Property and equipment, net	446,057	456,497
Operating lease assets	65,302	0
Goodwill, net	2,392,972	2,391,954
Other intangible assets, net	391,994	468,405
Capitalized data and database costs, net	323,777	324,049
Investment in affiliates, net	18,575	22,429
Other assets	75,518	102,136
Total assets	4,138,455	4,168,990
Current liabilities:
Accounts payable and other accrued expenses	179,740	166,258
Accrued salaries and benefits	80,570	84,940
Contract liabilities, current	314,847	308,959
Current portion of long-term debt	68,247	26,935
Operating lease liabilities, current	16,839	0
Total current liabilities	660,243	587,092
Long-term debt, net of current	1,636,272	1,752,241
Contract liabilities, net of current	539,037	524,069
Deferred income tax liabilities	100,229	124,968
Operating lease liabilities, net of current	85,844	0
Other liabilities	183,969	180,122
Total liabilities	3,205,594	3,168,492
Stockholders' equity:
Preferred stock, $0.00001 par value; 500 shares authorized, no shares issued or outstanding	0	0
Common stock, $0.00001 par value; 180,000 shares authorized; 79,519 and 80,092 shares issued and outstanding as of September 30, 2019 and December 31, 2018, respectively	1	1
Additional paid-in capital	124,872	160,870
Retained earnings	994,673	975,375
Accumulated other comprehensive loss	(186,685)	(135,748)
Total stockholders' equity	932,861	1,000,498
Total liabilities and equity	$ 4,138,455	$ 4,168,990