CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Cash flows from operating activities:
Net income	$ 31,433	$ 88,357	$ 72,691
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	36,220	27,597	26,172
Stock-based compensation expense	18,895	13,899	12,106
Provision for doubtful accounts	8,570	7,741	7,840
Gain on cash surrender value of life insurance policies	(3,984)	(10,509)	(8,242)
Loss (gain) on marketable securities	3,333	(8,829)	(9,498)
Deferred income taxes	(18,913)	(316)	7,598
Change in other assets and liabilities, net of effect of acquisitions:
Deferred compensation	(4,605)	10,130	12,186
Receivables due from clients	(16,622)	(17,213)	(22,318)
Income taxes and other receivables	(191)	115	896
Prepaid expenses and other assets	(6,310)	(1,145)	(1,255)
Investment in unconsolidated subsidiaries	(1,631)	(2,181)	(2,169)
Income taxes payable	899	(9,194)	7,533
Accounts payable and accrued liabilities	18,862	17,790	29,104
Other	(1,875)	(8,966)	(3,162)
Net cash provided by operating activities	64,081	107,276	129,482
Cash flows from investing activities:
Cash paid for acquisitions, net of cash acquired and earnout	(256,082)	(15,296)
Acquisition of Mexican subsidiary, cash acquired	3,973
Purchase of property and equipment	(26,144)	(21,860)	(28,559)
Purchase of marketable securities	(30,397)	(22,843)	(28,150)
Proceeds from sales/maturities of marketable securities	30,066	21,362	44,475
Change in restricted cash			2,861
Payment of contingent consideration from acquisition			(15,000)
Premiums on company-owned life insurance policies	(1,623)	(1,676)	(1,727)
Proceeds from life insurance policies	3,256	8,087	388
Dividends received from unconsolidated subsidiaries	2,373	1,656	2,120
Net cash used in investing activities	(274,578)	(30,570)	(23,592)
Cash flows from financing activities:
Proceeds from term loan facility	150,000
Principal payment on term loan facility	(10,000)
Purchase of common stock	(7,410)	(4,038)	(2,249)
Proceeds from issuance of common stock upon exercise of employee stock options and in connection with an employee stock purchase plan	4,038	2,993	8,805
Tax benefit related to stock-based compensation	4,908	1,516	(593)
Dividends paid to shareholders	(21,833)	(5,105)
Payments on life insurance policy loans	(1,251)	(3,301)	(388)
Net cash provided by (used in) financing activities	118,452	(7,935)	5,575
Effect of exchange rate changes on cash and cash equivalents	(15,541)	(21,650)	(1,814)
Net (decrease) increase in cash and cash equivalents	(107,586)	47,121	109,651
Cash and cash equivalents at beginning of year	380,838	333,717	224,066
Cash and cash equivalents at end of year	273,252	380,838	333,717
Supplemental cash flow information:
Cash used to pay interest	5,154	4,230	4,229
Cash used to pay income taxes, net of refunds	$ 33,189	$ 40,899	$ 15,604