CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 123,544	$ 116,645
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	7,823	8,223
Amortization of intangibles	55,694	51,828
Asset impairment charges	2,149	8,250
Amortization of prepaid product discounts	11,124	9,588
Deferred income taxes	(2,747)	(6,942)
Employee share-based compensation expense	5,757	7,309
Other non-cash items, net	(7,543)	(2,983)
Changes in assets and liabilities, net of effect of acquisitions:
Trade accounts receivable	16,670	15,401
Inventories and supplies	(1,245)	637
Other current assets	(12,435)	(2,779)
Non-current assets	(3,400)	(1,776)
Accounts payable	2,858	(12,063)
Prepaid product discount payments	13,282	10,937
Other accrued and non-current liabilities	(38,031)	(28,823)
Net cash provided by operating activities	146,936	151,578
Cash flows from investing activities:
Purchases of capital assets	(28,040)	(22,788)
Payments for acquisitions, net of cash acquired	(90,205)	(77,553)
Proceeds from sales of marketable securities	0	3,500
Other	682	739
Net cash used by investing activities	(117,563)	(96,102)
Cash flows from financing activities:
Proceeds from issuing long-term debt	908,000	168,000
Payments on long-term debt	(851,410)	(207,052)
Proceeds from issuing shares under employee plans	5,767	5,914
Employee taxes paid for shares withheld	(7,947)	(5,572)
Payments for common shares repurchased	(39,996)	(30,068)
Cash dividends paid to shareholders	(28,762)	(29,156)
Other	(3,921)	(511)
Net cash used by financing activities	(18,269)	(98,445)
Effect of exchange rate change on cash	(1,750)	1,175
Net change in cash and cash equivalents	9,354	(41,794)
Cash and cash equivalents, beginning of year	59,240	76,574
Cash and cash equivalents, end of period	$ 68,594	$ 34,780