Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Sep. 26, 2014
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Aggregate amount of goodwill acquired	$ 241,100,000	$ 241,100,000	$ 237,300,000
Aggregate amount of impairment	70,900,000	70,900,000	17,100,000
Goodwill, impairment charge		53,762,000
Goodwill balance	170,153,000	$ 170,153,000	220,163,000	$ 165,861,000
Additional impairment evaluation, description		A 1% increase in the selected discount rate would have resulted in zero, $0.4 million, and $2.8 million, of additional impairment for the SAT, Duall, and GPS reporting units, respectively. A 5% decrease in the selected multiples of revenue and EBITDA would have resulted in zero, $0.2 million, and $1.7 million, of additional impairment for the SAT, Duall, and GPS reporting units, respectively.
Increase in discount rate		1.00%
Decrease in selected multiples of revenue and EBITDA		5.00%
Intangible assets – indefinite life	22,042,000	$ 22,042,000	26,337,000	19,766,000
Impairment of intangible assets		4,161,000	3,340,000
Asset impairment charges		0
Amortization expense of finite life intangible assets		13,900,000	$ 12,300,000	$ 7,600,000
Amortization expense of finite life intangibles for 2017	11,500,000	11,500,000
Amortization expense of finite life intangibles for 2018	10,000,000	10,000,000
Amortization expense of finite life intangibles for 2019	8,800,000	8,800,000
Amortization expense of finite life intangibles for 2020	7,100,000	7,100,000
Amortization expense of finite life intangibles for 2021	5,800,000	5,800,000
Weighted average amortization period for finite lived assets acquired			8 years 8 months 12 days	9 years 10 months 24 days
SAT Technology, Inc. ("SAT") [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Goodwill, impairment charge	1,700,000
Goodwill balance	0	0
Duall [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Goodwill, impairment charge	5,100,000
Goodwill balance	5,400,000	5,400,000
Global Pump Solutions (GPS) [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Goodwill, impairment charge	46,900,000
Goodwill balance	26,800,000	26,800,000
Three Reporting Units [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Goodwill, impairment charge			$ 0	$ 0
Intangible assets – indefinite life	$ 16,500,000	$ 16,500,000
Fair value lower than the aggregate carrying value	25.20%	25.20%
Impairment of intangible assets		$ 4,200,000	$ 3,300,000	$ 0
PMFG, Inc. [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Decrease in property and equipment		5,500,000
Decrease in current assets		1,700,000
Decrease in deferred income tax liability		1,100,000
Decrease in noncontrolling interest		1,800,000
Goodwill balance	$ 59,860,000	59,860,000
Impairment of intangible assets		1,600,000
SAT Technology, Inc. ("SAT") [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Goodwill balance					$ 1,733,000
Additional goodwill impairment loss		0
Decrease in EBITDA results in additional impairment		0
Impairment of intangible assets		300,000
Duall [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Additional goodwill impairment loss		400,000
Decrease in EBITDA results in additional impairment		200,000
Impairment of intangible assets		500,000
Global Pump Solutions (GPS) [Member]
Schedule Of Goodwill And Other Intangible Assets [Line Items]
Additional goodwill impairment loss		2,800,000
Decrease in EBITDA results in additional impairment		1,700,000
Impairment of intangible assets		$ 1,800,000