Description of Business and Summary of Significant Accounting Policies Deferred Revenue Rollforward (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($)
Revenue Recognition and Deferred Revenue [Abstract]
Deferred Revenue, beginning of period	$ 44,660
Recognition of Deferred Revenue	(17,587)
Deferred Revenue acquired in acquisition	0
Deferred Revenue, Additions	14,749
Deferred Revenue, end of period	$ 41,822

The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by or used in operations using the indirect method.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

Name:	us-gaap_RecognitionOfDeferredRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration