Goodwill and Identifiable Intangible Assets, Net - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Changes in the carrying amount of goodwill
Balance at beginning of year	$ 611,789	$ 592,114
Acquisitions and purchase price adjustments (See Note 5)	55,045	19,675
Balance at end of period	666,834	611,789
Mechanical Segment
Changes in the carrying amount of goodwill
Balance at beginning of year	363,929	361,320
Acquisitions and purchase price adjustments (See Note 5)	29,347	2,609
Balance at end of period	393,276	363,929
Accumulated impairment charges	116,600	116,600
Electrical Segment
Changes in the carrying amount of goodwill
Balance at beginning of year	247,860	230,794
Acquisitions and purchase price adjustments (See Note 5)	25,698	17,066
Balance at end of period	$ 273,558	$ 247,860