CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 19,505	$ 15,527
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	8,652	7,546
Amortization of marketable securities	1,279	985
Stock-based compensation	4,956	4,346
Deferred income taxes	1,001	1,379
Changes in operating assets and liabilities,net of effects from acquisitions:
Restricted cash	157	(127)
Accounts receivable	(5,495)	7,018
Prepaid insurance	3,148	455
Other current assets	3,355	(1,217)
Other assets	(4,991)	5,909
Accounts payable	(2,212)	(885)
Payroll taxes and other payroll deductions payable	(46,062)	(46,886)
Accrued worksite employee payroll expense	14,568	61,379
Accrued health insurance costs	441	(2,994)
Accrued workers' compensation costs	2,382	4,850
Accrued corporate payroll, commissions and otheraccrued liabilities	(7,515)	(3,537)
Income taxes payable/receivable	4,090	562
Total adjustments	(22,246)	38,783
Net cash provided by (used in) operating activities	(2,741)	54,310
Cash flows from investing activities:
Marketable securities purchases	(14,818)	(13,903)
Marketable securities proceeds from dispositions	13,401	17,387
Marketable securities proceeds from maturities	0	1,365
Cash exchanged for acquisitions	(1,200)	(11,450)
Property and equipment	(8,331)	(8,404)
Net cash used in investing activities	(10,948)	(15,005)
Cash flows from financing activities:
Purchase of treasury stock	(11,741)	(6,639)
Dividends paid	(8,285)	(7,953)
Proceeds from the exercise of stock options	1,044	3,283
Income tax benefit from stock-based compensation	1,434	1,880
Other	619	486
Net cash used in financing activities	(16,929)	(8,943)
Net increase (decrease) in cash and cash equivalents	(30,618)	30,362
Cash and cash equivalents at beginning of period	211,208	234,829
Cash and cash equivalents at end of period	$ 180,590	$ 265,191