CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating activities
Net income	$ 14,503	$ 7,761
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	28,302	39,070
Deferred income taxes	1,977	2,276
Stock-based compensation	8,803	5,070
Excess tax benefit from equity incentive plan activity	(17,673)	(3,029)
Accretion of workers compensation and leases fair value adjustment	(358)	(695)
Changes in operating assets and liabilities:
Restricted cash and investments	(13,413)	10,520
Prepaid expenses and other current assets	(5,082)	(3,960)
Workers compensation receivables	(5,083)	(14,737)
Other assets	(14,509)	4,871
Accounts payable	(35)	3,405
Prepaid income taxes	23,953	(6,461)
Other current liabilities	(612)	(753)
Other liabilities	25,532	11,745
Worksite employee related assets	796,897	108,158
Worksite employee related liabilities	(798,024)	(109,584)
Net cash provided by operating activities	45,178	53,657
Investing activities
Purchase of debt securities		(16,789)
Purchase of property and equipment	(10,349)	(8,709)
Net cash used in investing activities	(10,349)	(25,498)
Financing activities
Proceeds from issuance of common stock, net of issuance costs		218,613
Proceeds from issuance of common stock on exercised options	4,639	631
Proceeds from issuance of common stock on employee stock purchase plan	2,723
Excess tax benefit from equity incentive plan activity	17,673	3,029
Repayment of notes payable	(35,187)	(243,025)
Repayments under capital leases	(138)	(188)
Repurchase of common stock	(30,358)	(1,288)
Net cash used in financing activities	(40,648)	(22,228)
Effect of exchange rate changes on cash and cash equivalents	(109)	1
Net increase (decrease) in cash and cash equivalents	(5,928)	5,932
Cash and cash equivalents at beginning of period	134,341	94,356
Cash and cash equivalents at end of period	128,413	100,288
Supplemental disclosures of cash flow information
Cash paid for interest	7,806	23,407
Cash paid for income taxes, net	1,505	11,067
Supplemental schedule of noncash investing and financing activities
Payable for purchase of property and equipment	$ 116	$ 3,970