CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 49,646	$ 42,406
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	8,659	8,447
Stock-based compensation	9,806	8,336
Deferred income taxes	8,465	9,414
Changes in operating assets and liabilities:
Restricted cash	934	(3,808)
Accounts receivable	8,715	(44,347)
Prepaid insurance	(12,029)	(19,128)
Other current assets	1,533	(1,419)
Other assets	(16,287)	4,156
Accounts payable	(1,057)	(1,835)
Payroll taxes and other payroll deductions payable	(57,826)	(64,180)
Accrued worksite employee payroll expense	13,342	115,459
Accrued health insurance costs	219	13,277
Accrued workers’ compensation costs	12,832	15,176
Accrued corporate payroll, commissions and other accrued liabilities	(11,974)	(11,627)
Income taxes payable/receivable	(1,929)	(9,661)
Total adjustments	(36,597)	18,260
Net cash provided by operating activities	13,049	60,666
Marketable securities:
Purchases	(919)	(310)
Proceeds from dispositions	0	7,268
Proceeds from maturities	805	990
Property and equipment:
Purchases	(20,802)	(12,647)
Net cash used in investing activities	(20,916)	(4,699)
Cash flows from financing activities:
Purchase of treasury stock	(25,528)	(4,790)
Repurchase of common stock	0	(144,263)
Dividends paid	(11,579)	(9,997)
Borrowings under long-term debt agreement	0	124,400
Principal repayments	0	(20,000)
Other	830	718
Net cash used in financing activities	(36,277)	(53,932)
Net increase (decrease) in cash and cash equivalents	(44,144)	2,035
Cash and cash equivalents at beginning of period	286,034	269,538
Cash and cash equivalents at end of period	$ 241,890	$ 271,573