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).

Name:	us-gaap_AccountsPayableCurrent
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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130549-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

BASIS OF PRESENTATION - Effect of Adoption of ASU 2014-09 (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 02, 2018	Jan. 01, 2018	Dec. 31, 2017
REVENUES
Net sales	$ 658,504			$ 729,230	$ 1,989,969	$ 2,149,616
Costs and expenses
Cost of sales	558,060			633,087	1,685,685	1,867,070
Income from operations	18,950			21,739	59,369	55,631
Income before taxes	19,064			21,731	59,781	55,651
Net income	13,766	$ 18,226	$ 11,300	13,117	43,292	34,134
ASSETS
Accounts receivable, net	400,831				400,831		$ 464,250		$ 449,682
Inventories, net	105,283				105,283		95,884		106,753
Prepaid expenses and other current assets	6,068				6,068		5,605		5,737
Long-term accounts receivable							1,890
Other assets	1,442				1,442		1,724		5,638
LIABILITIES
Accounts payable	165,190				165,190		194,195		194,257
Accrued expenses and other liabilities	23,475				23,475		30,784		31,096
Accrued payroll	20,359				20,359		22,953		22,662
Deferred income taxes	16,125				16,125		16,125		15,696
STOCKHOLDERS' EQUITY
Retained earnings	428,162				428,162		$ 384,870		$ 383,673
Difference between Revenue Guidance in Effect before and after Topic 606 \| ASU 2014-09
REVENUES
Net sales	107,826				296,583
Costs and expenses
Cost of sales	107,575				295,540
Income from operations	224				808
Income before taxes	224				808
Net income	162				584
ASSETS
Accounts receivable, net	(4,463)				(4,463)			$ 14,568
Inventories, net	6,059				6,059			(10,869)
Prepaid expenses and other current assets	129				129			(132)
Long-term accounts receivable								1,890
Other assets	3,914				3,914			(3,914)
LIABILITIES
Accounts payable								(62)
Accrued expenses and other liabilities	4,670				4,670			(312)
Accrued payroll	(103)				(103)			291
Deferred income taxes	(205)				(205)			429
STOCKHOLDERS' EQUITY
Retained earnings	(613)				(613)			$ 1,197
Calculated under Revenue Guidance in Effect before Topic 606
REVENUES
Net sales	766,330			$ 729,230	2,286,552	$ 2,149,616
Costs and expenses
Cost of sales	665,635				1,981,225
Income from operations	19,174				60,177
Income before taxes	19,288				60,589
Net income	13,928				43,876
ASSETS
Accounts receivable, net	396,368				396,368
Inventories, net	111,342				111,342
Prepaid expenses and other current assets	6,197				6,197
Other assets	5,356				5,356
LIABILITIES
Accrued expenses and other liabilities	28,145				28,145
Accrued payroll	20,256				20,256
Deferred income taxes	15,920				15,920
STOCKHOLDERS' EQUITY
Retained earnings	$ 427,549				$ 427,549