Net Sales and Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Product Information [Line Items]
Net sales	$ 325,130	$ 222,022	$ 742,209	$ 656,039
America's [Member]
Product Information [Line Items]
Net sales	116,710	77,374	260,682	225,115
EMEA [Member]
Product Information [Line Items]
Net sales	82,468	51,346	184,280	164,753
Asia Pacific [Member]
Product Information [Line Items]
Net sales	74,266	49,928	165,234	143,388
Transferred At Point In Time [Member]
Product Information [Line Items]
Net sales	316,847	217,392	724,831	641,219
Transferred At Point In Time [Member] | America's [Member]
Product Information [Line Items]
Net sales	150,906	107,957	352,504	309,810
Transferred At Point In Time [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	85,579	55,437	194,911	177,548
Transferred At Point In Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	80,362	53,998	177,416	153,861
Transferred Over Time [Member]
Product Information [Line Items]
Net sales	8,283	4,630	17,378	14,820
Transferred Over Time [Member] | America's [Member]
Product Information [Line Items]
Net sales	4,617	2,809	10,308	8,628
Transferred Over Time [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	1,960	62	2,065	172
Transferred Over Time [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	1,706	1,759	5,005	6,020
Primary Metals [Member]
Product Information [Line Items]
Net sales	112,889	97,603	299,705	290,975
Primary Metals [Member] | America's [Member]
Product Information [Line Items]
Net sales	45,782	42,052	126,145	123,618
Primary Metals [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	26,440	23,998	75,330	77,047
Primary Metals [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	40,667	31,553	98,230	90,310
Metalworking and other[Member]
Product Information [Line Items]
Net sales	160,555	81,045	310,491	242,281
Metalworking and other[Member] | America's [Member]
Product Information [Line Items]
Net sales	70,928	35,322	134,537	101,497
Metalworking and other[Member] | EMEA [Member]
Product Information [Line Items]
Net sales	56,028	27,348	108,950	87,706
Metalworking and other[Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	33,599	18,375	67,004	53,078
Global Specialty Businesses [Member]
Product Information [Line Items]
Net sales	51,686	43,374	132,013	122,783
Global Specialty Businesses [Member] | America's [Member]
Product Information [Line Items]
Net sales	38,813	33,392	102,130	93,323
Global Specialty Businesses [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	5,071	4,153	12,696	12,967
Global Specialty Businesses [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	7,802	5,829	17,187	16,493
Total sales with Global Specialty Businesses [Member]
Product Information [Line Items]
Net sales	325,130	222,022	742,209	656,039
Total sales with Global Specialty Businesses [Member] | America's [Member]
Product Information [Line Items]
Net sales	155,523	110,766	362,812	318,438
Total sales with Global Specialty Businesses [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	87,539	55,499	196,976	177,720
Total sales with Global Specialty Businesses [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	82,068	55,757	182,421	159,881
Total sales without Global Specialty Businesses [Member]
Product Information [Line Items]
Net sales	273,444	178,648	610,196	533,256
Total sales without Global Specialty Businesses [Member] | America's [Member]
Product Information [Line Items]
Net sales	116,710	77,374	260,682	225,115
Total sales without Global Specialty Businesses [Member] | EMEA [Member]
Product Information [Line Items]
Net sales	82,468	51,346	184,280	164,753
Total sales without Global Specialty Businesses [Member] | Asia Pacific [Member]
Product Information [Line Items]
Net sales	$ 74,266	$ 49,928	$ 165,234	$ 143,388