Equity - Non-controlling Interests (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Income attributable to non-controlling interests	$ 4,771	$ 2,661	$ 3,247
Carrying value of the investments held by Quanta in variable interest entities	12,000	9,600
Non-controlling interests	3,539	1,294
Distributions to non-controlling interests	2,526	4,038	2,001
Discharge of notes receivable		1,400	$ 500
VIE
Variable Interest Entity [Line Items]
Non-controlling interests	$ 3,500	$ 1,300