Acquisitions (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Sep. 30, 2016	Apr. 06, 2016	Dec. 31, 2015	Jul. 02, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 182,185			$ 121,829		$ 68,253
JPS Industries, Inc.
Business Acquisition [Line Items]
Cash and cash equivalents					$ 22
Trade and other receivables					21,201
Inventories					27,126
Prepaid and other current assets					4,961
Property, plant and equipment					45,384
Goodwill					32,162
Other intangibles					9,120
Deferred income tax assets					19,788
Other non-current assets					3,112
Total assets acquired					162,876
Trade payables					(10,674)
Accrued liabilities					(5,838)
Long-term debt					(1,500)
Accrued pension liability					(30,367)
Other liabilities					(4)
Net assets acquired					$ 114,493
SL Industries, Inc. (SLI)
Business Acquisition [Line Items]
Cash and cash equivalents			$ 4,985
Trade and other receivables			32,680
Inventories			24,088
Prepaid and other current assets			8,254
Property, plant and equipment			23,950
Goodwill			54,150
Other intangibles			92,326
Other non-current assets			257
Total assets acquired			240,690
Trade payables			(18,433)
Accrued liabilities			(18,521)
Long-term debt			(9,500)
Deferred income tax liabilities			(26,469)
Other liabilities			$ (5,782)
SL Industries, Inc. (SLI) | Electromagnetic Enterprise (EME)
Business Acquisition [Line Items]
Trade and other receivables		$ 4,249
Inventories		3,047
Prepaid and other current assets		265
Property, plant and equipment		2,321
Goodwill		30,645
Other intangibles		28,370
Total assets acquired		68,897
Trade payables		(3,440)
Accrued liabilities		(2,882)
Net assets acquired		$ 62,575