Revenue Recognition (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) unit	Dec. 31, 2018 USD ($) unit	Dec. 31, 2017 USD ($) unit
Disaggregation of Revenue [Line Items]
Net sales	$ 469,333	$ 433,947	$ 405,232
Total Units | unit	26,307,000	25,152,000	23,381,000
Rooftop Units
Disaggregation of Revenue [Line Items]
Net sales	$ 349,427	$ 333,105	$ 317,414
Total Units | unit	14,448,000	15,273,000	16,003,000
Condensing Units
Disaggregation of Revenue [Line Items]
Net sales	$ 18,475	$ 18,282	$ 19,276
Total Units | unit	1,738,000	2,007,000	2,252,000
Air Handlers
Disaggregation of Revenue [Line Items]
Net sales	$ 24,265	$ 21,905	$ 22,570
Total Units | unit	2,372,000	2,500,000	2,577,000
Outdoor Mechanical Rooms
Disaggregation of Revenue [Line Items]
Net sales	$ 1,643	$ 2,408	$ 3,238
Total Units | unit	33,000	38,000	64,000
Water Source Heat Pumps
Disaggregation of Revenue [Line Items]
Net sales	$ 25,447	$ 14,660	$ 9,911
Total Units | unit	7,716,000	5,334,000	2,485,000
Part Sales
Disaggregation of Revenue [Line Items]
Net sales	$ 33,331	$ 26,732	$ 20,756
Other
Disaggregation of Revenue [Line Items]
Net sales	$ 16,745	$ 16,855	$ 12,067