Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash Flows from Operating Activities
Net income	$ 44,667	$ 44,996
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	10,229	9,294
Litigation settlement	6,000
Stock option expense	4,089	3,653
Benefit for deferred income taxes	(3,489)	(2,807)
Noncash long-term incentive compensation	1,119	1,721
Amortization of debt issuance costs	76	128
Amortization of restricted stock awards		291
Changes in operating assets and liabilities:
(Increase)/decrease in accounts receivable	(81)	1,591
(Increase)/decrease in inventories	(610)	60
Decrease in prepaid expenses	6	1,045
Increase/(decrease) in accounts payable and other current liabilities	348	(7,911)
Change in current income taxes	9,219	13,642
Increase in other assets	(5,006)	(4,263)
Increase in other liabilities	6,459	3,758
Other sources/(uses)	559	(5)
Net cash provided by operating activities	73,585	65,193
Cash Flows from Investing Activities
Capital expenditures	(13,866)	(12,648)
Business combinations		(1,450)
Other (uses)/sources	(68)	181
Net cash used by investing activities	(13,934)	(13,917)
Cash Flows from Financing Activities
Proceeds from revolving line of credit	125,100	134,300
Payments on revolving line of credit	(114,300)	(90,500)
Purchases of treasury stock	(49,250)	(81,125)
Change in cash overdrafts payable	(13,303)	(6,671)
Proceeds from exercise of stock options	11,827	8,923
Capital stock surrendered to pay taxes on stock-based compensation	(11,170)	(6,377)
Dividends paid	(4,799)	(4,533)
Payments on other long-term debt		(2,500)
Other sources/(uses)	181	(228)
Net cash used by financing activities	(55,714)	(48,711)
Increase in Cash and Cash Equivalents	3,937	2,565
Cash and cash equivalents at beginning of year	4,831	11,121
Cash and cash equivalents at end of period	$ 8,768	$ 13,686