Revenue (Tables)

6 Months Ended

Jun. 30, 2018

Revenue From Contract With Customer [Abstract]

Net Sales and (Loss) Income before Income Taxes (Detail)

Net sales and (loss) income before income taxes and equity income in joint venture by geographic area for the three and six months ended June 30, 2018, and 2017, were as follows:

									(Loss) Income Before Income Taxes and
	Net Sales								Equity Income in Joint Venture
	Three Months Ended June 30,				Six Months Ended June 30,				Three Months Ended June 30,						Six Months Ended June 30,
	2018		2017		2018		2017		2018			2017			2018			2017
United States	$	65,601	$	60,590	$	124,152	$	116,092	$	(1,347	)	$	(5,805	)	$	(3,522	)	$	(10,691	)
Foreign		61,826		49,960		118,352		97,974		(805	)		3,469			2,318			3,778
	$	127,427	$	110,550	$	242,504	$	214,066	$	(2,152	)	$	(2,336	)	$	(1,204	)	$	(6,913	)

Net sales by product line for the three and six months ended June 30, 2018, and 2017, were as follows:

	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
Forged and cast mill rolls	$	74,927	$	61,720	$	142,415	$	125,972
Forged engineered products		28,059		26,637		54,479		44,088
Heat exchange coils		7,325		6,514		13,726		13,435
Centrifugal pumps		9,389		9,976		17,764		20,160
Air handling systems		7,727		5,703		14,120		10,411
	$	127,427	$	110,550	$	242,504	$	214,066

Schedule of Changes in Customer Deposits

Changes in customer deposits consisted of the following:

	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Balance at beginning of the period	$	4,702		$	7,942		$	4,573		$	6,786
Satisfaction of performance obligations		(2,637	)		(4,337	)		(5,149	)		(6,425	)
Receipt of additional deposits		2,876			4,219			5,513			7,459
Other, primarily changes in foreign currency    exchange rates		(52	)		25			(48	)		29
Balance at end of the period	$	4,889		$	7,849		$	4,889		$	7,849