Goodwill and Other Intangibles, Net - Reconciliation (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Goodwill [Line Items]
Gross goodwill	$ 170,530	$ 167,423
Accumulated impairments	0	0
Goodwill [Roll Forward]
Balance at beginning of year	167,423
Acquisitions	1,144
Impairments	0
Currency translation adjustment	1,509
Other adjustments	454
Balance at end of year	170,530
Diversified Industrial
Goodwill [Line Items]
Gross goodwill	169,305	167,342
Accumulated impairments	0	0
Goodwill [Roll Forward]
Balance at beginning of year	167,342
Acquisitions	0
Impairments	0
Currency translation adjustment	1,509
Other adjustments	454
Balance at end of year	169,305
Energy
Goodwill [Line Items]
Gross goodwill	1,144	0
Accumulated impairments	0	0
Goodwill [Roll Forward]
Balance at beginning of year	0
Acquisitions	1,144
Impairments	0
Currency translation adjustment	0
Other adjustments	0
Balance at end of year	1,144
Corporate and Other
Goodwill [Line Items]
Gross goodwill	81	81
Accumulated impairments	0	$ 0
Goodwill [Roll Forward]
Balance at beginning of year	81
Acquisitions	0
Impairments	0
Currency translation adjustment	0
Other adjustments	0
Balance at end of year	$ 81