Condensed Consolidating Financial Statements - Balance Sheet (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Mar. 31, 2014
Dec. 31, 2013
Current assets        
Cash and cash equivalents $ 865,201 $ 1,011,952 $ 684,715 $ 387,241
Accounts receivable, net 1,369,196 1,254,336    
Rebates receivable 836,136 863,824    
Other current assets 214,275 219,435    
Intercompany receivable 0 0    
Total current assets 3,284,808 3,349,547    
Property and equipment, net 198,988 210,027    
Goodwill 4,923,665 4,724,639    
Other intangible assets, net 980,480 968,199    
Intercompany loans receivable 0      
Investment in subsidiaries 0 0    
Other long-term assets 70,430 71,773    
Total assets 9,458,371 9,324,185 8,794,473  
Current liabilities        
Accounts payable 1,068,398 967,791    
Accrued expenses and other current liabilities 272,384 327,190    
Rebates payable 955,623 967,733    
Current portion - long-term debt 87,500 81,250    
Intercompany payable 0 0    
Total current liabilities 2,383,905 2,343,964    
Deferred income taxes 269,836 257,325    
Long-term debt 1,327,744 1,344,973    
Intercompany loans payable 0      
Other long-term liabilities 99,331 98,816    
Total liabilities 4,080,816 4,045,078    
Commitments and contingencies (Note 10)          
Shareholders’ equity        
Total shareholders' equity 5,369,653 5,271,979    
Non-controlling interest 7,902 7,128    
Total equity 5,377,555 5,279,107 4,986,787 4,911,498
Total liabilities and equity 9,458,371 9,324,185    
Reportable Legal Entities [Member] | Catamaran Corporation [Member]        
Current assets        
Cash and cash equivalents 36,057 333,469 201,288 15,090
Accounts receivable, net 4,010 304    
Rebates receivable 9,652 10,710    
Other current assets 120 99    
Intercompany receivable 0 0    
Total current assets 49,839 344,582    
Property and equipment, net 297 110    
Goodwill 0 0    
Other intangible assets, net 0 0    
Intercompany loans receivable 275,000      
Investment in subsidiaries 6,471,100 6,375,214    
Other long-term assets 12,895 13,874    
Total assets 6,809,131 6,733,780    
Current liabilities        
Accounts payable 0 4    
Accrued expenses and other current liabilities 4,452 10,580    
Rebates payable 0 0    
Current portion - long-term debt 87,500 81,250    
Intercompany payable 18,961 23,898    
Total current liabilities 110,913 115,732    
Deferred income taxes 0 0    
Long-term debt 1,327,744 1,344,973    
Intercompany loans payable 0      
Other long-term liabilities 821 1,096    
Total liabilities 1,439,478 1,461,801    
Commitments and contingencies (Note 10)          
Shareholders’ equity        
Total shareholders' equity 5,369,653 5,271,979    
Non-controlling interest 0 0    
Total equity 5,369,653 5,271,979    
Total liabilities and equity 6,809,131 6,733,780    
Reportable Legal Entities [Member] | Guarantors [Member]        
Current assets        
Cash and cash equivalents 683,546 648,903 477,255 362,647
Accounts receivable, net 1,323,025 1,217,675    
Rebates receivable 823,696 851,929    
Other current assets 144,676 166,858    
Intercompany receivable 534,122 675,551    
Total current assets 3,509,065 3,560,916    
Property and equipment, net 148,677 154,413    
Goodwill 4,689,522 4,689,522    
Other intangible assets, net 913,389 963,096    
Intercompany loans receivable 0      
Investment in subsidiaries 553,491 266,096    
Other long-term assets 43,474 42,876    
Total assets 9,857,618 9,676,919    
Current liabilities        
Accounts payable 1,335,543 1,079,598    
Accrued expenses and other current liabilities 233,059 304,309    
Rebates payable 955,623 967,733    
Current portion - long-term debt 0 0    
Intercompany payable 0 0    
Total current liabilities 2,524,225 2,351,640    
Deferred income taxes 268,288 255,777    
Long-term debt 0 0    
Intercompany loans payable 275,000      
Other long-term liabilities 72,191 71,475    
Total liabilities 3,139,704 2,678,892    
Commitments and contingencies (Note 10)          
Shareholders’ equity        
Total shareholders' equity 6,717,914 6,998,027    
Non-controlling interest 0 0    
Total equity 6,717,914 6,998,027    
Total liabilities and equity 9,857,618 9,676,919    
Reportable Legal Entities [Member] | Non-Guarantors [Member]        
Current assets        
Cash and cash equivalents 145,598 29,580 6,172 9,504
Accounts receivable, net 329,088 166,937    
Rebates receivable 152,144 155,719    
Other current assets 69,467 52,478    
Intercompany receivable 0 0    
Total current assets 696,297 404,714    
Property and equipment, net 50,014 55,504    
Goodwill 234,143 35,117    
Other intangible assets, net 67,091 5,103    
Intercompany loans receivable 0      
Investment in subsidiaries 71 71    
Other long-term assets 21,987 22,084    
Total assets 1,069,603 522,593    
Current liabilities        
Accounts payable 4,162 3,150    
Accrued expenses and other current liabilities 41,418 18,846    
Rebates payable 43,283 42,932    
Current portion - long-term debt 0 0    
Intercompany payable 614,771 626,434    
Total current liabilities 703,634 691,362    
Deferred income taxes 1,548 1,548    
Long-term debt 0 0    
Intercompany loans payable 0      
Other long-term liabilities 26,319 26,245    
Total liabilities 731,501 719,155    
Commitments and contingencies (Note 10)          
Shareholders’ equity        
Total shareholders' equity 336,857 (197,807)    
Non-controlling interest 1,245 1,245    
Total equity 338,102 (196,562)    
Total liabilities and equity 1,069,603 522,593    
Consolidations [Member]        
Current assets        
Cash and cash equivalents 0 0 0 0
Accounts receivable, net (286,927) (130,580)    
Rebates receivable (149,356) (154,534)    
Other current assets 12 0    
Intercompany receivable (534,122) (675,551)    
Total current assets (970,393) (960,665)    
Property and equipment, net 0 0    
Goodwill 0 0    
Other intangible assets, net 0 0    
Intercompany loans receivable (275,000)      
Investment in subsidiaries (7,024,662) (6,641,381)    
Other long-term assets (7,926) (7,061)    
Total assets (8,277,981) (7,609,107)    
Current liabilities        
Accounts payable (271,307) (114,961)    
Accrued expenses and other current liabilities (6,545) (6,545)    
Rebates payable (43,283) (42,932)    
Current portion - long-term debt 0 0    
Intercompany payable (633,732) (650,332)    
Total current liabilities (954,867) (814,770)    
Deferred income taxes 0 0    
Long-term debt 0 0    
Intercompany loans payable (275,000)      
Other long-term liabilities 0 0    
Total liabilities (1,229,867) (814,770)    
Commitments and contingencies (Note 10)          
Shareholders’ equity        
Total shareholders' equity (7,054,771) (6,800,220)    
Non-controlling interest 6,657 5,883    
Total equity (7,048,114) (6,794,337)    
Total liabilities and equity $ (8,277,981) $ (7,609,107)