Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 406,815	$ 296,007	$ 318,225
Other comprehensive income (loss), net of taxes:
Foreign currency translation adjustment, net of tax of $0, $0 and $0	43,535	(84,484)	67,404
Other, net of tax of $(200), $(677) and $(347)	695	1,831	874
Other comprehensive income (loss), net of taxes	44,230	(82,653)	68,278
Comprehensive income	451,045	213,354	386,503
Less: Comprehensive income attributable to non-controlling interests	4,771	2,661	3,247
Total comprehensive income attributable to Quanta stockholders	$ 446,274	$ 210,693	$ 383,256