Revenue - Revenues by Segment and Product Type (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	100.00%	100.00%
Energy [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	61.00%	66.00%
Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	26.00%	22.00%
Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	13.00%	12.00%
PLP-USA [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	100.00%	100.00%
PLP-USA [Member] | Energy [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	60.00%	59.00%
PLP-USA [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	33.00%	35.00%
PLP-USA [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	7.00%	6.00%
The Americas [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	100.00%	100.00%
The Americas [Member] | Energy [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	51.00%	70.00%
The Americas [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	44.00%	26.00%
The Americas [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	5.00%	4.00%
EMEA [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	100.00%	100.00%
EMEA [Member] | Energy [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	63.00%	73.00%
EMEA [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	25.00%	13.00%
EMEA [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	12.00%	14.00%
Asia-Pacific [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	100.00%	100.00%
Asia-Pacific [Member] | Energy [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	68.00%	72.00%
Asia-Pacific [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	4.00%	4.00%
Asia-Pacific [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	28.00%	24.00%