Condensed Consolidating Financial Statements Income Statement (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Condensed Income Statements, Captions [Line Items]      
Revenue $ 21,581,890 $ 14,780,094 $ 9,940,120
Cost of revenue 20,221,837 13,654,449 9,206,744
Gross profit 1,360,053 1,125,645 733,376
Expenses:      
Selling, general and administrative 518,351 440,759 369,492
Depreciation of property and equipment 59,486 37,926 16,749
Amortization of intangible assets 213,220 203,192 130,116
Total expenses 791,057 681,877 516,357
Operating income 568,996 443,768 217,019
Interest and other expense, net 61,088 41,626 26,682
Equity in (income) of subsidiaries 0 0 0
Income before income taxes 507,908 402,142 190,337
Income tax expense 134,186 103,403 69,316
Net income 373,722 298,739 121,021
Less net income attributable to non-controlling interest 56,429 36,569 4,363
Net income attributable to the Company 317,293 262,170 116,658
Reportable Legal Entities | Catamaran Corporation      
Condensed Income Statements, Captions [Line Items]      
Revenue 40,141 34,875 15,343
Cost of revenue 33,917 30,217 12,306
Gross profit 6,224 4,658 3,037
Expenses:      
Selling, general and administrative 2,931 1,094 4,688
Depreciation of property and equipment 30 29 50
Amortization of intangible assets 0 0 0
Total expenses 2,961 1,123 4,738
Operating income 3,263 3,535 (1,701)
Interest and other expense, net 51,904 36,700 11,731
Equity in (income) of subsidiaries (365,934) (295,335) (130,090)
Income before income taxes 317,293 262,170 116,658
Income tax expense 0 0 0
Net income 317,293 262,170 116,658
Less net income attributable to non-controlling interest 0 0 0
Net income attributable to the Company 317,293 262,170 116,658
Reportable Legal Entities | Guarantors      
Condensed Income Statements, Captions [Line Items]      
Revenue 20,849,801 13,682,194 9,578,406
Cost of revenue 19,764,270 12,756,828 8,926,325
Gross profit 1,085,531 925,366 652,081
Expenses:      
Selling, general and administrative 418,400 374,435 322,843
Depreciation of property and equipment 53,932 35,005 14,784
Amortization of intangible assets 210,251 200,065 126,847
Total expenses 682,583 609,505 464,474
Operating income 402,948 315,861 187,607
Interest and other expense, net 3,007 (344) 13,577
Equity in (income) of subsidiaries (58,804) (51,924) (14,551)
Income before income taxes 458,745 368,129 188,581
Income tax expense 92,811 72,794 58,491
Net income 365,934 295,335 130,090
Less net income attributable to non-controlling interest 0 0 0
Net income attributable to the Company 365,934 295,335 130,090
Reportable Legal Entities | Non-Guarantors      
Condensed Income Statements, Captions [Line Items]      
Revenue 3,028,412 1,750,509 911,107
Cost of revenue 2,760,114 1,554,888 832,849
Gross profit 268,298 195,621 78,258
Expenses:      
Selling, general and administrative 97,020 65,230 41,961
Depreciation of property and equipment 5,524 2,892 1,915
Amortization of intangible assets 2,969 3,127 3,269
Total expenses 105,513 71,249 47,145
Operating income 162,785 124,372 31,113
Interest and other expense, net 6,177 5,270 1,374
Equity in (income) of subsidiaries 0 0 0
Income before income taxes 156,608 119,102 29,739
Income tax expense 41,375 30,609 10,825
Net income 115,233 88,493 18,914
Less net income attributable to non-controlling interest 0 0 0
Net income attributable to the Company 115,233 88,493 18,914
Consolidations      
Condensed Income Statements, Captions [Line Items]      
Revenue (2,336,464) (687,484) (564,736)
Cost of revenue (2,336,464) (687,484) (564,736)
Gross profit 0 0 0
Expenses:      
Selling, general and administrative 0 0 0
Depreciation of property and equipment 0 0 0
Amortization of intangible assets 0 0 0
Total expenses 0 0 0
Operating income 0 0 0
Interest and other expense, net 0 0 0
Equity in (income) of subsidiaries 424,738 347,259 144,641
Income before income taxes (424,738) (347,259) (144,641)
Income tax expense 0 0 0
Net income (424,738) (347,259) (144,641)
Less net income attributable to non-controlling interest 56,429 36,569 4,363
Net income attributable to the Company $ (481,167) $ (383,828) $ (149,004)