Selected Consolidated Financial Statements of Parent, Guarantors, Canada Company and Non-Guarantors (Details 3) (USD $) In Thousands, unless otherwise specified	1 Months Ended						3 Months Ended		6 Months Ended
	Jul. 31, 2012	Apr. 30, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Apr. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Cash Flows from Operating Activities:
Cash Flows from Operating Activities-Continuing Operations									$ 216,855	$ 241,213
Cash Flows from Operating Activities-Discontinued Operations									(4,665)	1,844
Cash Flows from Operating Activities									212,190	243,057
Cash Flows from Investing Activities:
Capital expenditures							(51,445)	(46,976)	(107,361)	(99,184)
Cash paid for acquisitions, net of cash acquired							(98,472)	(40,467)	(107,290)	(75,172)
Investment in restricted cash									(1,502)	(3)
Additions to customer relationship and acquisition costs							(5,136)	(8,184)	(8,144)	(11,077)
Investment in joint ventures										(458)
Proceeds from sales of property and equipment and other, net									1,862	29
Cash Flows from Investing Activities-Continuing Operations									(222,435)	(185,865)
Cash Flows from Investing Activities-Discontinued Operations									(6,136)	376,352
Cash Flows from Investing Activities									(228,571)	190,487
Cash Flows from Financing Activities:
Repayment of revolving credit and term loan facilities and other debt									(1,768,694)	(1,593,705)
Proceeds from revolving credit and term loan facilities and other debt									1,888,264	1,676,069
Early retirement of senior subordinated notes										(231,255)
Debt financing (repayment to) and equity contribution from (distribution to) noncontrolling interests, net									385	480
Stock repurchases									(38,052)	(260,970)
Parent cash dividends	(46,336)	(42,791)	(43,180)	(46,877)	(50,694)	(37,601)			(85,971)	(75,044)
Proceeds from exercise of stock options and employee stock purchase plan									11,029	69,501
Excess tax benefits from stock-based compensation									254	57
Payment of debt financing costs									(93)	(8,217)
Cash Flows from Financing Activities-Continuing Operations									7,122	(423,084)
Cash Flows from Financing Activities-Discontinued Operations									(39)	(411)
Cash Flows from Financing Activities									7,083	(423,495)
Effect of Exchange Rates on Cash and Cash Equivalents									(317)	2,682
Increase (Decrease) in Cash and Cash Equivalents									(9,615)	12,731
Cash and Cash Equivalents, Beginning of Period	170,230		179,845		271,424				179,845	258,693
Cash and Cash Equivalents, End of Period							170,230	271,424	170,230	271,424
Parent
Cash Flows from Operating Activities:
Cash Flows from Operating Activities-Continuing Operations									(87,906)	(92,332)
Cash Flows from Operating Activities									(87,906)	(92,332)
Cash Flows from Investing Activities:
Intercompany loans to subsidiaries									234,913	973,565
Investment in subsidiaries									(36,193)	(1,228)
Investment in restricted cash									(1,502)	(3)
Cash Flows from Investing Activities-Continuing Operations									197,218	972,334
Cash Flows from Investing Activities									197,218	972,334
Cash Flows from Financing Activities:
Repayment of revolving credit and term loan facilities and other debt										(396,200)
Early retirement of senior subordinated notes										(231,255)
Stock repurchases									(38,052)	(260,970)
Parent cash dividends									(85,971)	(75,044)
Proceeds from exercise of stock options and employee stock purchase plan									11,029	69,501
Excess tax benefits from stock-based compensation									254	57
Cash Flows from Financing Activities-Continuing Operations									(112,740)	(893,911)
Cash Flows from Financing Activities									(112,740)	(893,911)
Increase (Decrease) in Cash and Cash Equivalents									(3,428)	(13,909)
Cash and Cash Equivalents, Beginning of Period			3,428						3,428	13,909
Guarantors
Cash Flows from Operating Activities:
Cash Flows from Operating Activities-Continuing Operations									249,123	290,532
Cash Flows from Operating Activities-Discontinued Operations									(2,651)	1,544
Cash Flows from Operating Activities									246,472	292,076
Cash Flows from Investing Activities:
Capital expenditures									(55,276)	(57,961)
Cash paid for acquisitions, net of cash acquired									(9,043)	(5,378)
Intercompany loans to subsidiaries									(78,762)	(68,961)
Investment in subsidiaries									(36,193)	(1,228)
Additions to customer relationship and acquisition costs									(6,179)	(8,515)
Proceeds from sales of property and equipment and other, net									1,898	188
Cash Flows from Investing Activities-Continuing Operations									(183,555)	(141,855)
Cash Flows from Investing Activities-Discontinued Operations									(1,982)	376,567
Cash Flows from Investing Activities									(185,537)	234,712
Cash Flows from Financing Activities:
Repayment of revolving credit and term loan facilities and other debt									(1,712,961)	(1,141,952)
Proceeds from revolving credit and term loan facilities and other debt									1,856,000	1,624,900
Intercompany loans from parent									(239,345)	(970,727)
Equity contribution from parent									36,193	1,228
Payment of debt financing costs									(93)	(8,217)
Cash Flows from Financing Activities-Continuing Operations									(60,206)	(494,768)
Cash Flows from Financing Activities									(60,206)	(494,768)
Increase (Decrease) in Cash and Cash Equivalents									729	32,020
Cash and Cash Equivalents, Beginning of Period			10,750						10,750	121,584
Cash and Cash Equivalents, End of Period							11,479	153,604	11,479	153,604
Canada Company
Cash Flows from Operating Activities:
Cash Flows from Operating Activities-Continuing Operations									19,935	7,790
Cash Flows from Operating Activities									19,935	7,790
Cash Flows from Investing Activities:
Capital expenditures									(7,000)	(4,445)
Cash paid for acquisitions, net of cash acquired										(58)
Additions to customer relationship and acquisition costs									(350)	(288)
Proceeds from sales of property and equipment and other, net									5	41
Cash Flows from Investing Activities-Continuing Operations									(7,345)	(4,750)
Cash Flows from Investing Activities									(7,345)	(4,750)
Cash Flows from Financing Activities:
Repayment of revolving credit and term loan facilities and other debt									(1,447)	(1,474)
Intercompany loans from parent									(1,758)	89
Cash Flows from Financing Activities-Continuing Operations									(3,205)	(1,385)
Cash Flows from Financing Activities									(3,205)	(1,385)
Effect of Exchange Rates on Cash and Cash Equivalents									344	1,414
Increase (Decrease) in Cash and Cash Equivalents									9,729	3,069
Cash and Cash Equivalents, Beginning of Period			68,907						68,907	37,652
Cash and Cash Equivalents, End of Period							78,636	40,721	78,636	40,721
Non-Guarantors
Cash Flows from Operating Activities:
Cash Flows from Operating Activities-Continuing Operations									35,703	35,223
Cash Flows from Operating Activities-Discontinued Operations									(2,014)	300
Cash Flows from Operating Activities									33,689	35,523
Cash Flows from Investing Activities:
Capital expenditures									(45,085)	(36,778)
Cash paid for acquisitions, net of cash acquired									(98,247)	(69,736)
Additions to customer relationship and acquisition costs									(1,615)	(2,274)
Investment in joint ventures										(458)
Proceeds from sales of property and equipment and other, net									(41)	(200)
Cash Flows from Investing Activities-Continuing Operations									(144,988)	(109,446)
Cash Flows from Investing Activities-Discontinued Operations									(4,154)	(215)
Cash Flows from Investing Activities									(149,142)	(109,661)
Cash Flows from Financing Activities:
Repayment of revolving credit and term loan facilities and other debt									(54,286)	(54,079)
Proceeds from revolving credit and term loan facilities and other debt									32,264	51,169
Debt financing (repayment to) and equity contribution from (distribution to) noncontrolling interests, net									385	480
Intercompany loans from parent									84,952	66,034
Equity contribution from parent									36,193	1,228
Cash Flows from Financing Activities-Continuing Operations									99,508	64,832
Cash Flows from Financing Activities-Discontinued Operations									(39)	(411)
Cash Flows from Financing Activities									99,469	64,421
Effect of Exchange Rates on Cash and Cash Equivalents									(661)	1,268
Increase (Decrease) in Cash and Cash Equivalents									(16,645)	(8,449)
Cash and Cash Equivalents, Beginning of Period			96,760						96,760	85,548
Cash and Cash Equivalents, End of Period							80,115	77,099	80,115	77,099
Eliminations
Cash Flows from Investing Activities:
Intercompany loans to subsidiaries									(156,151)	(904,604)
Investment in subsidiaries									72,386	2,456
Cash Flows from Investing Activities-Continuing Operations									(83,765)	(902,148)
Cash Flows from Investing Activities									(83,765)	(902,148)
Cash Flows from Financing Activities:
Intercompany loans from parent									156,151	904,604
Equity contribution from parent									(72,386)	(2,456)
Cash Flows from Financing Activities-Continuing Operations									83,765	902,148
Cash Flows from Financing Activities									$ 83,765	$ 902,148