Business Segments - Business Segment Net Sales and (Loss) Income before Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenue from External Customer [Line Items]
Net sales	$ 92,126	$ 82,861	$ 93,301	$ 63,578	$ 55,326	$ 58,094	$ 59,973	$ 65,087	$ 331,866	$ 238,480	$ 272,858
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(57,520)	4,520	(892)
Capital Expenditures									10,566	9,407	13,309
Depreciation and Amortization Expense									20,463	11,787	11,818
Identifiable Assets	565,889				506,156				565,889	506,156	536,409
Long-Lived Assets	339,601				265,905				339,601	265,905	284,098
Heat Exchange Coils [Member]
Revenue from External Customer [Line Items]
Net sales									28,139	32,745	39,109
Centrifugal Pumps [Member]
Revenue from External Customer [Line Items]
Net sales									36,359	33,120	32,983
Air Handling Systems [Member]
Revenue from External Customer [Line Items]
Net sales									19,716	20,348	21,378
Operating Segments [Member]
Revenue from External Customer [Line Items]
Net sales									331,866	238,480	272,858
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(37,755)	19,722	8,602
Corporate Costs, Including Other Income (Expense) [Member]
Revenue from External Customer [Line Items]
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(19,765)	(15,202)	(9,494)
Capital Expenditures									741	305	69
Depreciation and Amortization Expense									114	57	71
Identifiable Assets	44,541				94,414				44,541	94,414	78,507
U.S. [Member]
Revenue from External Customer [Line Items]
Net sales									159,531	126,417	143,493
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(25,906)	5,855	(1,471)
Long-Lived Assets	206,460				236,707				206,460	236,707	252,739
Foreign [Member]
Revenue from External Customer [Line Items]
Net sales									172,335	112,063	129,365
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(31,614)	(1,335)	579
Long-Lived Assets	133,141				29,198				133,141	29,198	31,359
Forged and Cast Engineered Products [Member]
Revenue from External Customer [Line Items]
Net sales									247,652	152,267	179,388
Write off of goodwill associated with the Akers acquisition									26,676
Forged and Cast Engineered Products [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Net sales									247,652	152,267	179,388
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									(42,878)	(3,444)	4,380
Capital Expenditures									9,440	8,608	12,884
Depreciation and Amortization Expense									19,166	10,468	10,303
Identifiable Assets	348,331				228,718				348,331	228,718	260,384
Air and Liquid Processing [Member] | Operating Segments [Member]
Revenue from External Customer [Line Items]
Net sales									84,214	86,213	93,470
(Loss) Income Before Income Taxes and Equity Losses in Chinese Joint Venture									5,123	23,166	4,222
Capital Expenditures									385	494	356
Depreciation and Amortization Expense									1,183	1,262	1,444
Identifiable Assets	$ 173,017				$ 183,024				$ 173,017	$ 183,024	$ 197,518