Condensed Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Revenue	$ 1,304,686	$ 1,273,150	$ 3,931,824	$ 4,078,861
Operating costs and expenses:
Cost of revenue	641,541	662,053	1,928,967	2,048,663
Billable expenses	366,371	320,370	1,064,994	1,083,890
General and administrative expenses	176,327	175,748	524,368	520,557
Depreciation and amortization	15,191	17,945	47,233	54,377
Total operating costs and expenses	1,199,430	1,176,116	3,565,562	3,707,487
Operating income	105,256	97,034	366,262	371,374
Interest expense	(17,863)	(18,874)	(54,544)	(59,761)
Other, net	(777)	21	(1,080)	(1,619)
Income before income taxes	86,616	78,181	310,638	309,994
Income tax expense	33,809	31,014	121,432	124,701
Net income	$ 52,807	$ 47,167	$ 189,206	$ 185,293
Earnings per common share (Note 3):
Basic (in dollars per share)	$ 0.35	$ 0.32	$ 1.28	$ 1.31
Diluted (in dollars per share)	$ 0.35	$ 0.31	$ 1.24	$ 1.24
Dividends declared per share	$ 0.11	$ 1.10	$ 1.33	$ 1.30