Goodwill and Identifiable Intangible Assets, Net - Changes in Carrying Amount of Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Changes in the carrying amount of goodwill
Balance at beginning of year	$ 666,834	$ 611,789
Acquisitions and purchase price adjustments (See Note 5)	208,359	55,045
Balance at end of period	875,193	666,834
Mechanical Segment
Changes in the carrying amount of goodwill
Balance at beginning of year	393,276	363,929
Acquisitions and purchase price adjustments (See Note 5)	208,159	29,347
Balance at end of period	601,435	393,276
Electrical Segment
Changes in the carrying amount of goodwill
Balance at beginning of year	273,558	247,860
Acquisitions and purchase price adjustments (See Note 5)	200	25,698
Balance at end of period	$ 273,758	$ 273,558