CONSOLIDATED STATEMENTS OF OTHER COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
CONSOLIDATED STATEMENTS OF OTHER COMPREHENSIVE INCOME
Net income	$ 32,042	$ 231,194	$ 55,569	$ 253,311
Other comprehensive income (loss), net of tax:
Amortization of actuarial loss on defined benefit pension plan, net	4	0	9	0
Unrealized gain (loss) on marketable securities, available-for-sale	236	(851)	424	(975)
Other comprehensive income (loss), net of tax	240	(851)	433	(975)
Comprehensive income	$ 32,282	$ 230,343	$ 56,002	$ 252,336