Quanta Services, Inc. Annual report pursuant to Section 13 and 15(d)

Debt Obligations - Long-term Debt Obligations (Parenthetical) (Detail)	Dec. 31, 2015	Dec. 31, 2014
Minimum [Member] \| Other Long Term Debt [Member]
Debt Instrument [Line Items]
Capital leases and Other long-term debt interest rates	3.40%	3.40%
Minimum [Member] \| Capital Leases [Member]
Debt Instrument [Line Items]
Capital leases and Other long-term debt interest rates	2.50%	2.50%
Maximum [Member] \| Other Long Term Debt [Member]
Debt Instrument [Line Items]
Capital leases and Other long-term debt interest rates	4.30%	4.30%
Maximum [Member] \| Capital Leases [Member]
Debt Instrument [Line Items]
Capital leases and Other long-term debt interest rates	6.20%	6.20%