Long-Term Debt (Tables)

3 Months Ended

Mar. 31, 2014

Debt Disclosure [Abstract]

Schedule of maturities of long-term debt

As of March 31, 2014, maturities of long-term debt for the years ending December 31 are as follows (in thousands):

	Total		2014		2015		2016		2017		2018		Thereafter
1.125% Notes	$	550,000	$	—	$	—	$	—	$	—	$	—	$	550,000
3.75% Notes	187,000		187,000		—		—		—		—		—
	$	737,000	$	187,000	$	—	$	—	$	—	$	—	$	550,000

Long term debt

The principal amounts, unamortized discount and net carrying amounts of the convertible senior notes were as follows:

	Principal Balance		Unamortized Discount		Net Carrying Amount
	(In thousands)
March 31, 2014:
1.125% Notes	$	550,000	$	128,996	$	421,004
3.75% Notes	187,000		3,451		183,549
	$	737,000	$	132,447	$	604,553
December 31, 2013:
1.125% Notes	$	550,000	$	133,632	$	416,368
3.75% Notes	187,000		5,128		181,872
	$	737,000	$	138,760	$	598,240

Debt instruments interest cost recognized

	Three Months Ended March 31,
	2014		2013
	(In thousands)
Interest cost recognized for the period relating to the:
Contractual interest coupon rate	$	3,300	$	2,527
Amortization of the discount	6,314		3,723
Total interest cost recognized	$	9,614	$	6,250