Acquisitions, Goodwill And Other Intangible Assets (Schedule Of Business Acquisitions) (Details) - USD ($) $ in Thousands	1 Months Ended							3 Months Ended	9 Months Ended
	Aug. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Aug. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Feb. 28, 2014	Dec. 31, 2014	Sep. 30, 2014	Sep. 30, 2015	Apr. 30, 2014
Business Acquisition
Goodwill (tax deductible)								$ 66,521	$ 66,203	$ 84,551
EA Technologies
Business Acquisition
Cash consideration			$ 9,248					$ 6,600
Net tangible assets			8,868
Total fair value of net assets acquired			9,348
Gain on bargain purchase			100
Signature Seating
Business Acquisition
Cash consideration	$ 16,000
Contingent consideration	3,556
Total fair value of consideration given	$ 19,556
Net tangible assets										4,091
Total fair value of net assets acquired										10,591
Gain on bargain purchase									8,965
Spectal Industries
Business Acquisition
Cash consideration		$ 22,335
Contingent consideration		1,211
Total fair value of consideration given		$ 23,546
Net tangible assets											$ 3,681
Total fair value of net assets acquired											14,481
Goodwill (tax deductible)											9,065
Duncan Systems
Business Acquisition
Cash consideration				$ 18,000
Contingent consideration				1,914
Total fair value of consideration given				$ 19,914
Net tangible assets									4,070
Total fair value of net assets acquired									15,500
Goodwill (tax deductible)									4,414
Power Gear and Kwikee Brands
Business Acquisition
Cash consideration					$ 35,500
Net tangible assets									2,227
Total fair value of net assets acquired									21,957
Goodwill (tax deductible)									13,543
Star Design
Business Acquisition
Cash consideration						$ 12,232
Net tangible assets						2,108
Total fair value of net assets acquired						7,118
Goodwill (tax deductible)						5,114
Innovative Design Solutions
Business Acquisition
Cash consideration							$ 34,175
Present value of future payments							1,739
Contingent consideration							710
Total fair value of consideration given							36,624
Net tangible assets							1,894
Total fair value of net assets acquired							15,074
Goodwill (tax deductible)							21,550
Customer Relationships | EA Technologies
Business Acquisition
Intangible assets, excluding goodwill			400
Customer Relationships | Signature Seating
Business Acquisition
Intangible assets, excluding goodwill										$ 6,500
Customer Relationships | Spectal Industries
Business Acquisition
Intangible assets, excluding goodwill											10,100
Customer Relationships | Duncan Systems
Business Acquisition
Intangible assets, excluding goodwill									10,500
Customer Relationships | Power Gear and Kwikee Brands
Business Acquisition
Intangible assets, excluding goodwill									12,300
Customer Relationships | Star Design
Business Acquisition
Intangible assets, excluding goodwill						4,400
Customer Relationships | Innovative Design Solutions
Business Acquisition
Intangible assets, excluding goodwill							4,000
Patents | Power Gear and Kwikee Brands
Business Acquisition
Intangible assets, excluding goodwill									5,300
Patents | Innovative Design Solutions
Business Acquisition
Intangible assets, excluding goodwill							6,000
Other Intangible Assets | EA Technologies
Business Acquisition
Intangible assets, excluding goodwill			$ 80
Other Intangible Assets | Spectal Industries
Business Acquisition
Intangible assets, excluding goodwill											$ 700
Other Intangible Assets | Duncan Systems
Business Acquisition
Intangible assets, excluding goodwill									930
Other Intangible Assets | Power Gear and Kwikee Brands
Business Acquisition
Intangible assets, excluding goodwill									$ 2,130
Other Intangible Assets | Star Design
Business Acquisition
Intangible assets, excluding goodwill						$ 610
Other Intangible Assets | Innovative Design Solutions
Business Acquisition
Intangible assets, excluding goodwill							$ 3,180