Identifiable Assets by Business Segment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Accounts receivable	$ 579,166	$ 537,704	$ 515,954
Goodwill	200,833	201,339	189,423
Temporary and consultant staffing
Segment Reporting Information [Line Items]
Accounts receivable	349,364	336,468	342,122
Goodwill	134,692	134,756	134,507
Permanent placement staffing
Segment Reporting Information [Line Items]
Accounts receivable	100,550	88,436	75,333
Goodwill	26,574	26,586	26,545
Risk consulting and internal audit services
Segment Reporting Information [Line Items]
Accounts receivable	129,252	112,800	98,499
Goodwill	$ 39,567	$ 39,997	$ 28,371