Statements of Consolidated Income (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Statements of Consolidated Income [Abstract]
Net sales	$ 114,530	$ 82,137	$ 209,618	$ 151,045
Cost of products sold	77,824	54,682	140,521	103,565
GROSS PROFIT	36,706	27,455	69,097	47,480
Costs and expenses
Selling	9,272	7,038	17,308	13,540
General and administrative	11,780	9,666	22,742	19,144
Research and engineering	3,215	2,700	6,577	5,559
Other operating (income) expense	(694)	1,135	(788)	990
Total costs and expenses	23,573	20,539	45,839	39,233
OPERATING INCOME	13,133	6,916	23,258	8,247
Other income (expense)
Interest income	140	94	291	177
Interest expense	(266)	(126)	(477)	(296)
Other income	43	409	227	760
Total other income (expense)	(83)	377	41	641
INCOME BEFORE INCOME TAXES	13,050	7,293	23,299	8,888
Income taxes	4,520	1,197	7,915	1,758
NET INCOME	8,530	6,096	15,384	7,130
Net income (loss) attributable to noncontrolling interest, net of tax	144			(98)
NET INCOME ATTRIBUTABLE TO PLPC	$ 8,386	$ 6,096	$ 15,384	$ 7,228
BASIC EARNINGS PER SHARE
Net income attributable to PLPC common shareholders	$ 1.59	$ 1.16	$ 2.92	$ 1.38
DILUTED EARNINGS PER SHARE
Net income attributable to PLPC common shareholders	$ 1.55	$ 1.13	$ 2.85	$ 1.34
Cash dividends declared per share	$ 0.20	$ 0.20	$ 0.40	$ 0.40
Weighted-average number of shares outstanding - basic	5,263	5,253	5,268	5,253
Weighted-average number of shares outstanding - diluted	5,393	5,402	5,390	5,401