Prepaid Expenses and Other Current Assets, Accrued Expenses, Other Current Liabilities, and Other Liabilities (Tables)

12 Months Ended

Dec. 31, 2018

Payables and Accruals [Abstract]

Components of Prepaid Expenses and Other Current Assets

The following table presents the components of selected balance sheet items as of December 31, 2018 and 2017 (in thousands):

	December 31,
Prepaid expenses and other current assets:	2018		2017
Deferred costs in transit	$	83,652	$	54,483
Supplier receivable	31,842		29,941
Supplier credits receivable	17,667		12,936
Other prepaid and other current assets	62,269		33,478
Total prepaid expenses and other current assets	$	195,430	$	130,838

Components of Accrued Expenses

	December 31,
Accrued expenses:	2018		2017
Employee compensation and related benefits	$	91,914	$	55,142
Advertising	67,259		38,888
Accrued property, plant and equipment	13,955		8,592
Credit card	16,740		4,573
Audit, legal and professional fees	1,703		1,749
Other accrued expenses	21,426		11,303
Total accrued expenses	$	212,997	$	120,247

Components of Other Liabilities

	December 31,
Other current liabilities:	2018		2017
Sales tax payable	$	49,989	$	35,726
Sales return reserve	35,707		21,243
Other current liabilities	42,299		28,057
Total current other liabilities	$	127,995	$	85,026

	December 31,
Other liabilities:	2018		2017
Deferred rent	$	99,746	$	59,811
Construction costs under build-to-suit leases	60,089		37,545
Other liabilities	553		9,136
Total other liabilities	$	160,388	$	106,492