Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating activities:
Net income (loss)	$ 29,418	$ (18,728)	$ (79,700)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation	21,823	21,498	16,931
Amortization of content databases	32,329	29,074	26,781
Amortization of acquired intangible assets	109,318	147,681	185,193
Amortization of debt-related costs	18,855	9,350	26,898
Deferred income taxes	(50,482)	(55,019)	(70,633)
Stock-based compensation expense	7,683	8,004	8,324
Excess tax benefit from stock-based compensation	(27)	(4,063)	(292)
Non-cash adjustment to deferred revenues	0	0	21,115
Changes in operating assets and liabilities:
Accounts receivable	(2,383)	141	(293)
Other assets	(4,185)	336	(1,878)
Income taxes, net	3,818	10,768	45,867
Accounts payable and other liabilities	6,638	(868)	(15,130)
Deferred revenues	26,812	7,146	(204)
Net cash provided by operating activities	199,617	155,320	162,979
Investing activities:
Capitalization of content databases	(32,514)	(37,566)	(22,239)
Purchases of property and equipment	(15,117)	(21,821)	(26,714)
Issuance of related-party note receivable	(10,000)	0	0
Acquisition of business, net of cash acquired	0	0	(9,000)
Net cash used in investing activities	(57,631)	(59,387)	(57,953)
Financing activities:
Member’s capital contributions	0	26	2,557
Proceeds from exercise of stock options	0	0	457
Taxes paid related to net share settlement of stock-based awards	0	0	(595)
Excess tax benefits from stock-based compensation	27	4,063	292
Proceeds from credit facilities	727,650	0	0
Principal payments on debt	(586,370)	(37,572)	(47,896)
Payment of debt-offering costs	(9,229)	0	(8,938)
Return-of-capital distributions	(254,401)	(37,610)	0
Payment of contingent consideration	0	(2,900)	0
Net cash used in financing activities	(122,323)	(73,993)	(54,123)
Net increase in cash and cash equivalents	19,663	21,940	50,903
Cash and cash equivalents at beginning of period	108,494	86,554	35,651
Cash and cash equivalents at end of period	128,157	108,494	86,554
Supplemental disclosures of cash flow information:
Cash paid for interest	62,831	60,450	70,311
Cash paid (received) for income taxes	23,333	1,334	(40,601)
Supplemental disclosures of non-cash investing and financing activities:
Increase in estimated cost of construction of a building under a build-to-suit lease	$ 22,900	$ 0	$ 0