Basis of Presentation and Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2013

Basis of Presentation and Summary of Significant Accounting Policies

Schedule of assets measured at fair value on a recurring basis

The following tables represent the fair value hierarchy as of March 31, 2013 and December 31, 2012 for those assets that we measure at fair value on a recurring basis (in thousands):

	Fair Value Measurements at March 31, 2013 Using:
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Money market funds	$	21,542	$	21,542	$	—	$	—
Corporate debt securities	124,710		—		124,710		—
U.S. treasury and government agency securities	54,517		—		54,517		—
Commercial paper	3,997		—		3,997		—
	$	204,766	$	21,542	$	183,224	$	—

	Fair Value Measurements at December 31, 2012 Using:
			Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
Money market funds	$	24,058	$	24,058	$	—	$	—
Corporate debt securities	111,690		—		111,690		—
U.S. treasury and government agency securities	59,569		—		59,569		—
Commercial paper	9,491		—		9,491		—
	$	204,808	$	24,058	$	180,750	$	—

Analysis of product sales allowances and accruals

An analysis of our product sales allowances and accruals for the three months ended March 31, 2013 and 2012 is as follows (in thousands):

	Three Months Ended March 31,
	2013			2012
Provision for U.S. product sales allowances and accruals
Discounts and chargebacks	$	7,493		$	5,892
Government and other rebates	2,387			1,460
Returns	193			(266		)
Total provision for U.S. product sales allowances and accruals	$	10,073		$	7,086
Total gross U.S. product sales	$	25,651		$	20,712
Total provision for U.S. product sales allowances and accruals as a percent of total gross U.S. product sales	39		%	34		%

Schedule of customers representing 10% or more of revenues

	Three Months Ended March 31,
	2013		2012
AmerisourceBergen Drug Corporation	43	%	45	%
McKesson Corporation	22	%	20	%
Cardinal Health, Inc.	15	%	15	%
Takeda Pharmaceuticals Company Limited	12	%	11	%