Revenue

9 Months Ended

Sep. 30, 2020

Revenue from Contract with Customer [Abstract]

Revenue

Revenue

Disaggregation of revenue

The following table shows net sales classified by major product category for the three and nine months ended September 30, 2020 and 2019:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2020		2019		2020		2019
Millwork, doors & windows	$	299,812	$	285,750	$	883,480	$	796,807
Structural components	185,910		175,344		510,789		483,575
Lumber & lumber sheet goods	383,626		274,908		935,582		798,722
Other building products & services	220,995		228,247		661,267		656,925
Total net sales	$	1,090,343	$	964,249	$	2,991,118	$	2,736,029

The following table reflects the Company’s estimate of net sales by each customer type for the three and nine months ended September 30, 2020 and 2019:

	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands)	2020		2019		2020		2019
Single-family homebuilders	$	811,081	$	718,690	$	2,188,240	$	2,064,382
Remodeling contractors	143,536		115,756		375,904		314,277
Multi-family, commercial & other contractors	135,726		129,803		426,974		357,370
Total net sales	$	1,090,343	$	964,249	$	2,991,118	$	2,736,029

Net sales for the Company's building products contracts was $850.9 million, $728.5 million, $2,276.9 million and $2,061.8 million for the three and nine months ended September 30, 2020 and 2019, respectively. Net sales for the Company's construction services contracts, which includes both products and installation services, was $239.5 million, $235.8 million, $714.2 million and $674.3 million for the three and nine months ended September 30, 2020 and 2019, respectively.

Contract balances

The following table reflects the Company’s contract balances as of September 30, 2020 and December 31, 2019:

(in thousands)	September 30, 2020		December 31, 2019		Change
Receivables, including unbilled receivables presented in prepaid expenses and other current assets	$	409,640	$	333,044	$	76,596
Contract assets	36,422		32,125		4,297
Contract liabilities	$	44,980	$	31,094	$	13,886

During the nine months ended September 30, 2020, the Company’s contract assets increased by $4.3 million and the Company’s contract liabilities increased by $13.9 million. The changes in contract assets and liabilities were primarily due to the timing of revenue recognition, as the balances were not materially impacted by any other factors. For the three and nine months ended September 30, 2020, the Company recognized revenue of $1.4 million and $29.2 million, respectively, that was included in contract liabilities as of December 31, 2019. Revenue recognized related to performance obligations that were satisfied or partially satisfied in previous periods was not material for the three and nine months ended September 30, 2020.

As permitted by ASC 606, Revenue from Contracts with Customers, the Company has elected not to disclose the value of unsatisfied performance obligations, as the Company’s contracts generally have an original expected length of one year or less.