Business Combinations - Additional Information (Detail) - USD ($) $ in Thousands																					3 Months Ended								12 Months Ended
	Nov. 14, 2016	Nov. 01, 2016	Oct. 17, 2016	Aug. 15, 2016	Jul. 25, 2016	Apr. 12, 2016	Feb. 29, 2016	Feb. 02, 2016	Jan. 25, 2016	Dec. 07, 2015	Nov. 10, 2015	Nov. 09, 2015	Aug. 10, 2015	Jul. 01, 2015	Jun. 01, 2015	Apr. 06, 2015	Mar. 12, 2015	Nov. 10, 2014	Aug. 11, 2014	Mar. 24, 2014	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
Business Acquisition [Line Items]
Goodwill acquired expected to be tax deductible																					$ 17,200								$ 17,200
Purchase price paid in cash																													53,312	$ 84,274	$ 12,364
Seller obligations in connection with acquisition of businesses																													4,459	13,180	3,544
Revenue																					233,977	$ 225,392	$ 211,913	$ 191,698	$ 191,499	$ 181,579	$ 159,693	$ 129,948	862,980	662,719	518,020
Net income (loss)																					11,081	$ 11,549	$ 9,993	$ 5,813	9,287	$ 9,481	$ 6,507	$ 1,242	38,436	26,517	13,932
Gain on bargain purchase																														1,116
Amortization of intangibles																													11,259	6,264	2,837
Income tax expense (benefit)																													21,174	15,413	8,607
Administrative [Member]
Business Acquisition [Line Items]
Acquisition-related costs																													2,300	1,100
Key Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash									$ 5,000
Seller obligations in connection with acquisition of businesses									$ 700
Revenue																													8,600
Net income (loss)																													(400)
Marshall Insulation LLC [Member]
Business Acquisition [Line Items]
Purchase price paid in cash								$ 900
Seller obligations in connection with acquisition of businesses								$ 100
Revenue																													3,800
Net income (loss)																													(300)
Kern Door Company [Member]
Business Acquisition [Line Items]
Purchase price paid in cash							$ 2,900
Seller obligations in connection with acquisition of businesses							$ 100
Revenue																													2,700
Net income (loss)																													(300)
BDI Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash																	$ 30,700
Seller obligations in connection with acquisition of businesses																	$ 5,800													5,765
Revenue																														32,500
Net income (loss)																														2,000
Ownership percentage acquired																	100.00%
Fair value of assets acquired																									36,445					36,445
Insurance receivable for claims under a fully insured policy																									2,000					2,000
Indemnification asset associated with the acquisition																									1,700					1,700
Combined Business Acquisitions [Member]
Business Acquisition [Line Items]
Seller obligations in connection with acquisition of businesses																													4,459	13,180	3,544
Fair value of assets acquired																					59,952				99,496				59,952	99,496	15,961
Gain on bargain purchase																														1,116
Amortization of intangibles																													1,400	6,600	6,800
Income tax expense (benefit)																													700	1,700	800
Transaction costs																									1,000					1,000
Alpine [Member]
Business Acquisition [Line Items]
Purchase price paid in cash						$ 21,100
Seller obligations in connection with acquisition of businesses						$ 1,600																							1,560
Revenue																													21,400
Net income (loss)																													1,400
Fair value of assets acquired																					22,711								22,711
FireClass, LLC [Member]
Business Acquisition [Line Items]
Purchase price paid in cash					$ 2,300
Revenue																													2,100
Net income (loss)																													69
Southern Insulators & Specialties LLC [Member]
Business Acquisition [Line Items]
Purchase price paid in cash				$ 4,200
Seller obligations in connection with acquisition of businesses				$ 400
Revenue																													1,900
Net income (loss)																													300
CQ Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash																$ 5,200
Seller obligations in connection with acquisition of businesses																$ 2,300														2,319
Revenue																														7,800
Net income (loss)																														600
Ownership percentage acquired																100.00%
Contingent upon certain requirements of the seller																$ 1,800
Fair value of assets acquired																									7,512					7,512
Layman Brothers Contracting [Member]
Business Acquisition [Line Items]
Purchase price paid in cash															$ 9,100
Seller obligations in connection with acquisition of businesses															$ 600															600
Revenue																														8,200
Net income (loss)																														500
Fair value of assets acquired																									9,688					9,688
EcoLogic Energy Solutions [Member]
Business Acquisition [Line Items]
Purchase price paid in cash														$ 3,000
Seller obligations in connection with acquisition of businesses														$ 500
Revenue																														3,900
Net income (loss)																														(200)
East Coast Insulators II, L.L.C [Member]
Business Acquisition [Line Items]
Purchase price paid in cash			$ 15,600
Seller obligations in connection with acquisition of businesses			$ 600																										600
Revenue																													4,700
Net income (loss)																													21
Fair value of assets acquired																					$ 16,189								16,189
Mike’s Garage Door, L.L.C [Member]
Business Acquisition [Line Items]
Purchase price paid in cash		$ 200
Seller obligations in connection with acquisition of businesses		$ 400
Revenue																													200
Net income (loss)																													(2)
3R Products & Services, LLC [Member]
Business Acquisition [Line Items]
Purchase price paid in cash	$ 3,300
Seller obligations in connection with acquisition of businesses	$ 600
Revenue																													700
Net income (loss)																													$ 40
Eastern Contractor Services [Member]
Business Acquisition [Line Items]
Purchase price paid in cash													$ 24,200
Seller obligations in connection with acquisition of businesses													$ 2,900																	2,875
Revenue																														7,400
Net income (loss)																														300
Ownership percentage acquired													100.00%
Fair value of assets acquired																									27,074					27,074
Sierra Insulation Contractors and Eco Tect Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash												$ 3,200
Seller obligations in connection with acquisition of businesses												$ 500
Revenue																														800
Net income (loss)																														40
Overhead Door Company [Member]
Business Acquisition [Line Items]
Purchase price paid in cash											$ 5,100
Seller obligations in connection with acquisition of businesses											$ 100
Revenue																														1,000
Net income (loss)																														14
Prime Energy [Member]
Business Acquisition [Line Items]
Purchase price paid in cash										$ 4,700
Seller obligations in connection with acquisition of businesses										$ 500
Revenue																														600
Net income (loss)																														20
U.S. Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash																				$ 2,000
Seller obligations in connection with acquisition of businesses																				$ 300
Revenue																															9,700
Net income (loss)																															800
Ownership percentage acquired																				100.00%
Marv's Insulation [Member]
Business Acquisition [Line Items]
Purchase price paid in cash																			$ 1,400
Seller obligations in connection with acquisition of businesses																			$ 200
Revenue																															1,500
Net income (loss)																															200
Ownership percentage acquired																			100.00%
IBS [Member]
Business Acquisition [Line Items]
Purchase price paid in cash																		$ 9,000
Seller obligations in connection with acquisition of businesses																		$ 3,000
Revenue																															2,300
Net income (loss)																															$ (5)
Business Combination Included as "Other" [Member]
Business Acquisition [Line Items]
Fair value of assets acquired																									$ 4,800					4,800
Total purchase price																														3,700
Gain on bargain purchase																														$ 1,100