Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Loss Carryforwards [Line Items]
Income before income taxes		$ 1,329,815	$ 1,225,097	$ 761,235
Current:
Federal		786,964	686,561	437,038
State		8,769	28,568	28,718
Current Foreign Tax Expense (Benefit)		(1,362)	4,004	2,879
Total current tax expense		794,371	719,133	468,635
Deferred:
Federal		(377,368)	(119,849)	(62,932)
State		13,431	(3,768)	18,891
Deferred Foreign Income Tax Expense (Benefit)		3,859	(6,475)	(1,485)
Total deferred tax (benefit) expense		(360,078)	(130,092)	(45,526)
Total income tax expense (benefit)		$ 434,293	$ 589,041	$ 423,109
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
U.S. federal statutory tax rate		35.00%	35.00%	35.00%
Stock-based compensation		(10.90%)	(0.00%)	(0.00%)
State and local income taxes		0.30%	1.00%	2.40%
Change in state effective rate		1.00%	(0.10%)	2.90%
Foreign income tax rate differential		8.80%	12.20%	15.80%
Income tax credits		(1.20%)	(1.60%)	(5.10%)
Non-deductible Branded Prescription Drug Fee		1.90%	2.00%	2.80%
Domestic production activities deduction		(2.80%)	(3.20%)	(0.00%)
Other permanent differences		0.60%	2.80%	1.80%
Effective income tax rate		32.70%	48.10%	55.60%
Deferred tax assets:
Net operating loss carryforward		$ 137	$ 140
Fixed and intangible assets		21,139	0
Deferred revenue		214,587	51,766
Deferred compensation		515,984	349,508
Capitalized research and development costs		2,492	7,725
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities		37,188	47,520
Other		46,471	26,580
Deferred tax assets, gross		837,998	483,239
Valuation allowance		(3,420)	0
Deferred tax assets, net		834,578	483,239
Deferred tax liabilities:
Accruals		0	(3,280)
Deferred Tax Liabilities, Property, Plant and Equipment		0	(5,559)
Deferred Tax Liabilities, Other		(9,275)	(12,455)
Deferred tax liabilities, gross		(9,275)	(21,294)
Deferred Tax Assets, Net		825,303	461,945
Utilization of net operating loss carryforwards related to exercises of Nonqualified Stock Options and disqualifying dispositions of ISOs, credited to additional paid-in capital			405,317	$ 439,278
Excess Tax Benefit from Share-based Compensation, Financing Activities		0	405,317	439,278
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		107,200	102,100	51,200
Other Comprehensive Income (Loss), Tax		3,300	24,900	27,100
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance as of January 1	$ 116,572	116,572	57,615	26,627
Gross increases related to current year tax positions		45,575	59,909	27,538
Unrecognized Tax Benefits, Period Increase (Decrease)		(42,284)	(952)	6,464
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		2,697	0	3,014
Balance as of December 31		117,166	116,572	57,615
Unrecognized Tax Benefits, Interest on Income Taxes Accrued		3,300
Decrease in Unrecognized Tax Benefits is Reasonably Possible		22,300
UNITED STATES
Operating Loss Carryforwards [Line Items]
Income before income taxes		1,650,959	1,665,087	1,101,446
Foreign
Operating Loss Carryforwards [Line Items]
Income before income taxes		(321,144)	(439,990)	(340,211)
Accounting Standards Update 2016-09 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
Deferred tax liabilities:
Excess Tax Benefit from Share-based Compensation, Financing Activities		$ 144,800
Additional Paid-in Capital
Deferred tax liabilities:
Utilization of net operating loss carryforwards related to exercises of Nonqualified Stock Options and disqualifying dispositions of ISOs, credited to additional paid-in capital			$ 405,317	$ 439,278
Additional Paid-in Capital | Accounting Standards Update 2016-09 [Member] | New Accounting Pronouncement, Early Adoption, Effect [Member]
Deferred tax liabilities:
Excess Tax Benefit from Share-based Compensation, Financing Activities	$ 15,600