Summary of Significant Accounting Policies - Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Assets
Cash and cash equivalents	$ 283,644	$ 312,483	$ 172,128
Accounts receivable, net	805,413	609,670	629,235
Inventories	1,148,493	1,158,548	901,613
Prepaid expenses and other current assets	354,455	256,978	203,052
Total current assets	2,592,005	2,337,679	1,906,028
Non-current assets	1,672,314
Total assets	4,264,319	4,006,367	3,577,160
Liabilities
Revolving credit facility, current	135,000	125,000	50,000
Accounts payable	470,378	561,108	294,857
Accrued expenses	276,888	296,841	217,310
Customer refund liability	353,020	0	0
Current maturities of long term debt	27,000	27,000	27,000
Other current liabilities	54,771	50,426	38,372
Total current liabilities	1,317,057	1,060,375	627,539
Non-current liabilities	929,530
Total liabilities	2,246,587	1,987,725	1,557,127
Stockholders’ equity	2,017,732	2,018,642	2,020,033
Total liabilities and stockholders’ equity	4,264,319	$ 4,006,367	$ 3,577,160
Accounting Standards Update 2014-09 [Member]
Assets
Cash and cash equivalents	283,644
Accounts receivable, net	545,352
Inventories	1,151,985
Prepaid expenses and other current assets	257,689
Total current assets	2,238,670
Non-current assets	1,674,017
Total assets	3,912,687
Liabilities
Revolving credit facility, current	135,000
Accounts payable	470,378
Accrued expenses	276,888
Customer refund liability	0
Current maturities of long term debt	27,000
Other current liabilities	60,459
Total current liabilities	969,725
Non-current liabilities	929,530
Total liabilities	1,899,255
Stockholders’ equity	2,013,432
Total liabilities and stockholders’ equity	3,912,687
Accounting Standards Update 2014-09 [Member] \| ASC 606 Adjustments [Member]
Assets
Accounts receivable, net	(260,061)
Inventories	3,492
Prepaid expenses and other current assets	(96,766)
Total current assets	(353,335)
Non-current assets	1,703
Total assets	(351,632)
Liabilities
Revolving credit facility, current	0
Accounts payable	0
Accrued expenses	0
Customer refund liability	(353,020)
Current maturities of long term debt	0
Other current liabilities	5,688
Total current liabilities	(347,332)
Non-current liabilities	0
Total liabilities	(347,332)
Stockholders’ equity	(4,300)
Total liabilities and stockholders’ equity	$ (351,632)

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.