Revenue - Revenues by Segment and Product Type (Detail)	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 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	68.00%	69.00%
Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	19.00%	20.00%
Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	13.00%	11.00%
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	57.00%	58.00%
PLP-USA [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	36.00%	36.00%
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	77.00%	77.00%
The Americas [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	19.00%	19.00%
The Americas [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	4.00%	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	75.00%	78.00%
EMEA [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	6.00%	6.00%
EMEA [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	19.00%	16.00%
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	70.00%	74.00%
Asia-Pacific [Member] | Communications [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	4.00%	5.00%
Asia-Pacific [Member] | Special Industries [Member]
Disaggregation Of Revenue [Line Items]
Percentage of disaggregated revenue	26.00%	21.00%