Collaboration Agreements (Tables)

3 Months Ended

Mar. 31, 2018

Collaboration Agreement [Abstract]

Collaboration revenue with related party

The collaboration revenue we earned from Sanofi is detailed below:

	Three Months Ended March 31,
Sanofi Collaboration Revenue	2018			2017
Antibody:
Reimbursement of Regeneron research and development expenses	$	60,394		$	155,245
Reimbursement of Regeneron commercialization-related expenses	85,424			73,559
Regeneron's share of losses in connection with commercialization of antibodies	(74,874		)	(108,402		)
Other	17,330			11,286
Total Antibody	88,274			131,688
Immuno-oncology:
Reimbursement of Regeneron research and development expenses	73,824			58,679
Reimbursement of Regeneron commercialization-related expenses	1,210			—
Other	26,182			20,000
Total Immuno-oncology	101,216			78,679
	$	189,490		$	210,367

Schedule of Selected Financial Information - Antibody

The following table summarizes accounts receivable and deferred revenue information in connection with the Company's Antibody Collaboration with Sanofi:

	March 31,		December 31,
	2018		2017
Accounts receivable, net	$	94,022	$	121,001
Deferred revenue	$	132,991	$	117,682

Changes In Deferred Revenue Balance - Antibody

Significant changes in deferred revenue balances are as follows:

	Three Months Ended March 31, 2018
Increase due to shipments of commercial supplies to Sanofi	$	37,036
Revenue recognized that was included in deferred revenue at the beginning of the period	$	(21,727	)

Schedule of Selected Financial information - IO

The following table summarizes accounts receivable and deferred revenue information in connection with the Company's IO Collaboration with Sanofi:

	March 31,		December 31,
	2018		2017
Accounts receivable, net	$	70,887	$	59,274
Deferred revenue	$	505,235	$	440,000

Changes in Deferred Revenue Balance - IO

Significant changes in deferred revenue balances are as follows:

	Three Months Ended March 31, 2018
Increase as a result of cumulative-effect adjustment arising from the adoption of ASC 606	$	93,643
Revenue recognized that was included in deferred revenue at the beginning of the period	$	(28,408	)

Collaboration revenue

Revenue earned in connection with our EYLEA collaboration with Bayer is detailed below:

	Three Months Ended March 31,
Bayer EYLEA Collaboration Revenue	2018		2017
EYLEA:
Regeneron's net profit in connection with commercialization of EYLEA outside the United States	$	232,068	$	174,876
Reimbursement of Regeneron EYLEA development expenses	3,457		2,451
Other	11,863		10,603
Total EYLEA	$	247,388	$	187,930

Schedule of Selected Financial Information - Bayer

The following table summarizes accounts receivable and deferred revenue information in connection with the Company's EYLEA collaboration with Bayer:

	March 31,		December 31,
	2018		2017
Accounts receivable, net	$	243,141	$	241,153
Deferred revenue	$	70,378	$	68,734

Changes In Deferred Revenue Balance - Bayer

Significant changes in deferred revenue balances are as follows:

	Three Months Ended March 31, 2018
Increase due to shipments of commercial supplies to Bayer	$	11,436
Revenue recognized that was included in deferred revenue at the beginning of the period	$	(9,792	)

Schedule of Selected Financial Information - Teva

The following tables summarize accounts receivable and deferred revenue information in connection with the Teva Collaboration Agreement:

	March 31,		December 31,
	2018		2017
Accounts receivable, net (recorded within Prepaid expenses and other current assets)	$	40,625	$	71,297
Deferred revenue	$	227,714	$	197,357

Changes in Deferred Revenue Balance - Teva

Significant changes in deferred revenue balances are as follows:

	Three Months Ended March 31, 2018
Increase as a result of cumulative-effect adjustment arising from the adoption of ASC 606	$	48,216
Revenue recognized that was included in deferred revenue at the beginning of the period	$	(18,917	)