Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 41,677	$ 31,416
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,491	3,773
Bad debt provision	940	1,750
Deferred income benefits	(2,312)	(2,990)
Stock-based compensation expense	1,791	1,699
Amortization of premium on marketable securities	449	496
Unrealized loss on marketable securities	0	82
Unrealized gain on deferred compensation fund investments	(1,711)	(1,712)
Changes in operating assets and liabilities:
Accounts and notes receivable	(46,119)	(9,776)
Prepaid income taxes	0	405
Inventories and supplies	(1,904)	(2,264)
Deferred compensation funding	(3,408)	(1,621)
Accounts payable and other accrued expenses	13,866	15,623
Accrued payroll, accrued and withheld payroll taxes	(11,945)	(9,386)
Accrued insurance claims	2,011	4,850
Deferred compensation liability	5,510	3,814
Income taxes payable	4,365	3,196
Prepaid expenses and other assets	171	(3,936)
Net cash provided by operating activities	7,872	35,419
Cash flows from investing activities:
Disposals of fixed assets	158	19
Additions to property and equipment	(2,735)	(2,668)
Purchases of marketable securities	(4,799)	(8,745)
Sales of marketable securities	13,970	18,090
Cash paid for acquisition	(5,000)	0
Net cash provided by investing activities	1,594	6,696
Cash flows from financing activities:
Dividends paid	(34,760)	(32,866)
Reissuance of treasury stock pursuant to Dividend Reinvestment Plan	80	89
Tax benefit from equity compensation plans	1,355	1,289
Proceeds from the exercise of stock options	5,469	3,910
Net cash used in financing activities	(27,856)	(27,578)
Net change in cash and cash equivalents	(18,390)	14,537
Cash and cash equivalents at beginning of the period	68,949	38,639
Cash and cash equivalents at end of the period	50,559	53,176
Supplementary Cash Flow Information:
Income taxes cash payments, net of refunds	14,923	17,416
Issuance of Common Stock in 2013 and 2012, respectively, pursuant to Employee Stock Plans	$ 1,842	$ 1,250

The component of income tax expense for the period representing the increase (decrease) in the entity's deferred tax assets and liabilities pertaining to continuing operations, less the amount attributable to the tax benefit from deferred compensation plan.

No definition available.