Consolidated Statement Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash Flows from Operating Activities
Net income	$ 51,512	$ 44,937
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	17,272	16,165
Deferred income taxes	(2,783)	6,180
Provision for uncollectible accounts receivable	7,734	6,449
Amortization of discount on convertible notes		3,392
Stock option expense	2,787	2,453
Amortization of debt issuance costs	262	564
Noncash long-term incentive compensation	2,391	986
Changes in operating assets and liabilities, excluding amounts acquired in business combinations:
Increase in accounts receivable	(2,182)	(6,782)
Increase in inventories	(78)	(153)
Increase in prepaid expenses	(507)	(3,301)
Decrease in accounts payable and other current liabilities	(1,314)	(33,584)
Increase/(decrease) in income taxes	(2,384)	7,224
Increase in other assets	(2,229)	(2,748)
Increase in other liabilities	2,966	4,644
Excess tax benefit on share-based compensation	(3,998)	(1,866)
Other sources	189	553
Net cash provided by operating activities	69,638	45,113
Cash Flows from Investing Activities
Capital expenditures	(18,846)	(19,454)
Business combinations, net of cash acquired	(6,614)	(250)
Other sources	395	192
Net cash used by investing activities	(25,065)	(19,512)
Cash Flows from Financing Activities
Proceeds from revolving line of credit	103,200	245,500
Payments on revolving line of credit	(88,200)	(185,500)
Payments on other long-term debt	(2,500)	(186,956)
Proceeds from other long-term debt		100,000
Purchases of treasury stock	(29,762)	(58,493)
Proceeds from exercise of stock options	8,044	16,092
Dividends paid	(7,459)	(6,757)
Capital stock surrendered to pay taxes on stock-based compensation	(5,876)	(3,543)
Retirement of warrants		(2,645)
Excess tax benefit on share-based compensation	3,998	1,866
Debt issuance costs		(939)
Decrease in cash overdrafts payable	(6,791)	(479)
Other uses	(654)	(252)
Net cash used by financing activities	(26,000)	(82,106)
Increase/(decrease) in cash and cash equivalents	18,573	(56,505)
Cash and cash equivalents at beginning of period	14,132	84,418
Cash and cash equivalents at end of period	$ 32,705	$ 27,913