Basis and Summary of Significant Accounting Policies - Components of the Accounts Receivable Provision (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015
Accounting Policies [Abstract]
Bad debt expense	$ 91,635	$ 87,817
Provision for returns and uncollected renewal payments	28,045	30,081
Accounts receivable provision	$ 119,680	$ 117,898

Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.5)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3602-108585

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Period Type:	duration