FAIR VALUE MEASUREMENTS: (Tables)

6 Months Ended

Jun. 30, 2016

Schedule of the fair value hierarchy of the Company's financial assets and liabilities measured at fair value

The following table represents the fair value hierarchy of the Company's financial assets and liabilities measured at fair value on a recurring basis as of June 30, 2016:



	Level 1		Level 2		Total
	(in thousands)
Money market funds	$	4,985	—		$	4,985
Certificates of deposit	—		57,486		57,486
U.S. Government and agency securities	—		43,908		43,908
Commercial paper	—		28,363		28,363
Corporate bonds	—		74,638		74,638
Municipal bonds	—		3,441		3,441
Foreign government bonds	—		5,118		5,118
	4,985		212,954		217,939
Derivative contracts	—		630		630
Total financial assets	$	4,985	$	213,584	$	218,569
Derivative contracts	$	—	$	524	$	524
Total financial liabilities	$	—	$	524	$	524

The following table represents the fair value hierarchy of the Company's financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2015:



	Level 1		Level 2		Total
	(in thousands)
Certificates of deposit	$	—	$	110,423	$	110,423
U.S. Government and agency securities	—		131,722		131,722
Commercial paper	—		57,214		57,214
Corporate bonds	—		105,482		105,482
Municipal bonds	—		26,208		26,208
Foreign government bonds	—		13,940		13,940
Total financial assets	$	—	$	444,989	$	444,989
Derivative contracts	$	—	$	1,157	$	1,157
Total financial liabilities	$	—	$	1,157	$	1,157

Company calculated a fair value amount of $271.6 million at June 30, 2016 based on a discounted cash flow model using observable market inputs and taking into consideration variables such as interest rate changes, comparable instruments, and long-term credit ratings.