Commitments and Contingencies Warranty Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Total warranty expense (benefit)	$ 1,528	$ (3,148)	$ 12,291	$ (5,318)
Unusual or Infrequent Item, or Both, Insurance Proceeds		$ 8,000		$ 8,000

Amount of insurance proceeds for an event or transaction that is unusual in nature or infrequent in occurrence, or both.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233

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