Segment Reporting (Schedule Of Segment Reporting Information By Segment) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Segment Reporting Information [Line Items]
Total net sales	$ 212,679	$ 197,954	$ 634,716	$ 581,703
Add back freight	6,130	4,636	17,404	13,377
Sales as shown in the Consolidated Statements of Income	218,809	202,590	652,120	595,080
Total	22,287	17,086	52,942	44,521
Interest income	84	278	337	778
Interest expense	708	367	2,732	1,083
Gain on investment accounted for under fair value method			9,000
Stock option-based compensation costs	386	474	1,147	1,481
Corporate expenses, net	4,789	3,920	17,206	10,954
Income from continuing operations before income taxes	19,188	12,603	41,194	31,781
Income taxes from continuing operations	4,661	(133)	11,516	6,329
Income from continuing operations	14,527	12,736	29,678	25,452
Loss from discontinued operations	(7,100)		(11,900)	(345)
Net income	7,427	12,736	17,778	25,107
Specialty Pharmaceutical Company [Member]
Segment Reporting Information [Line Items]
Gain on investment accounted for under fair value method	2,700		9,000
Income taxes from continuing operations	(1,209)	(112)	(3,100)	181
Net income	(1,880)	(202)	(4,926)	423
Film Products [Member]
Segment Reporting Information [Line Items]
Total net sales	155,296	129,733	459,221	393,289
Ongoing operations	21,092	15,485	49,999	43,872
Plant shutdowns, asset impairments, restructurings and other	(87)	(1,435)	(1,879)	(2,519)
Aluminum Extrusions [Member]
Segment Reporting Information [Line Items]
Total net sales	55,222	66,815	172,525	186,712
Ongoing operations	1,846	2,301	7,349	2,539
Plant shutdowns, asset impairments, restructurings and other	(1,067)	(43)	(3,214)	19
Other [Member]
Segment Reporting Information [Line Items]
Total net sales	2,161	1,406	2,970	1,702
Ongoing operations	$ 503	$ 778	$ 687	$ 610