Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 137,286	$ 105,185
Accounts receivable (less allowance for credit losses of $8,007 and $7,161 as of June 30, 2020 and December 31, 2019, respectively)	290,199	281,392
Prepaid expenses and other current assets	68,991	59,972
Total current assets	496,476	446,549
Property and equipment, net	440,015	451,021
Operating lease assets	59,571	65,825
Goodwill, net	2,400,412	2,396,096
Other intangible assets, net	351,055	378,818
Capitalized data and database costs, net	327,936	327,078
Investment in affiliates, net	11,839	16,666
Other assets	76,087	76,604
Total assets	4,163,391	4,158,657
Current liabilities:
Accounts payable and other accrued expenses	185,355	173,989
Accrued salaries and benefits	67,039	86,598
Contract liabilities, current	362,702	321,647
Current portion of long-term debt	2,504	56,022
Operating lease liabilities, current	17,855	18,058
Total current liabilities	635,455	656,314
Long-term debt, net of current	1,566,292	1,610,538
Contract liabilities, net of current	589,744	563,246
Deferred income tax liabilities	85,280	110,396
Operating lease liabilities, net of current	76,411	85,139
Other liabilities	208,086	181,814
Total liabilities	3,161,268	3,207,447
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; 79,459 and 78,972 shares issued and outstanding as of June 30, 2020 and December 31, 2019, respectively	1	1
Additional paid-in capital	120,029	111,000
Retained earnings	1,099,154	1,006,992
Accumulated other comprehensive loss	(217,061)	(166,783)
Total stockholders' equity	1,002,123	951,210
Total liabilities and equity	$ 4,163,391	$ 4,158,657
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0