CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 95,747	$ 90,442
Investments	9,923	10,060
Accounts receivable (less allowance for doubtful accounts of $5,539 and $5,085 at June 30, 2019 and December 31, 2018, respectively)	232,111	214,121
Inventories	63,951	61,162
Other current assets	34,944	35,760
Total current assets	436,676	411,545
Property and equipment, net	92,655	90,117
Operating lease right-of-use assets	46,383
Non-current assets
Goodwill	183,412	173,049
Intangibles, net	148,203	149,790
Other non-current assets	9,062	10,157
Total assets	916,391	834,658
Current liabilities
Current maturities of long-term debt	25,252	22,642
Current maturities of operating lease obligations	15,028
Current maturities of finance lease obligations	3,738	4,806
Accounts payable	96,235	96,949
Accrued compensation	26,964	27,923
Other current liabilities	34,760	29,366
Total current liabilities	201,977	181,686
Long-term debt	431,988	432,182
Operating lease obligations	30,964
Finance lease obligations	3,943	3,824
Deferred income taxes	4,421	6,695
Other long-term liabilities	37,096	27,773
Total liabilities	710,389	652,160
Commitments and contingencies
Stockholders' equity
Preferred Stock; $0.01 par value: 5,000,000 authorized and 0 shares issued and outstanding at June 30, 2019 and December 31, 2018, respectively
Common stock; $0.01 par value: 100,000,000 authorized, 32,871,504 and 32,723,972 issued and 30,017,008 and 29,915,611 shares outstanding at June 30, 2019 and December 31, 2018, respectively	329	327
Additional paid in capital	186,182	181,815
Retained earnings	132,965	105,212
Treasury stock; at cost: 2,854,496 and 2,808,361 shares at June 30, 2019 and December 31, 2018, respectively	(106,748)	(104,425)
Accumulated other comprehensive loss	(6,726)	(431)
Total stockholders' equity	206,002	182,498
Total liabilities and stockholders' equity	$ 916,391	$ 834,658

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