Borrowings (Tables)

3 Months Ended

Mar. 31, 2014

Debt Disclosure [Abstract]

Schedule of Future Minimum Payments under the Loans Payable

Future minimum payments under indebtedness agreements outstanding as of March 31, 2014are as follows:

As of March 31, 2014: (in thousands)	4.50% Convertible Senior Notes			Loan Agreement
Remainder of 2014	$	2,813		$	11,298
2015		5,625			18,130
2016		5,625			17,916
2017		5,625			—
2018 and thereafter		141,875			—
	$	161,563		$	47,344
Less interest		(36,563	)		(6,144	)
Less unamortized discount		(50,418	)		(1,971	)
Less current portion		—			(12,022	)
Loans payable, net of current portion	$	74,582		$	27,207