Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Name:	us-gaap_BusinessCombinationConsiderationTransferred1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Aug. 30, 2019	Aug. 21, 2018	Sep. 30, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill			$ 327,983	$ 323,671
Apeks
Business Acquisition [Line Items]
Aggregate consideration for acquisition	$ 12,600
Goodwill	$ 4,185
SolarBOS
Business Acquisition [Line Items]
Aggregate consideration for acquisition		$ 6,400
Goodwill		$ 2,879
Maximum \| Apeks
Business Acquisition [Line Items]
Working capital adjustment period	6 months
Minimum \| Apeks
Business Acquisition [Line Items]
Working capital adjustment period	3 months