13. Interest

Interest is capitalized to inventories while the related communities are being actively developed and until homes are completed. As our qualifying assets exceeded our outstanding debt during the years ended December 31, 2018, 2017, and 2016, we capitalized all interest costs incurred during these periods, except for interest incurred on our mortgage repurchase facilities.

Our interest costs are as follows (in thousands):



	Year ended December 31,
	2018		2017		2016
Interest capitalized beginning of period	$	41,762	$	28,935	$	21,533
Interest capitalized during period		60,772		45,725		26,904
Less: capitalized interest in cost of sales		(48,692)		(32,898)		(19,502)
Interest capitalized end of period	$	53,842	$	41,762	$	28,935