CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net (loss) income:	$ (271)	$ 14,609	$ (1,986)	$ 417,597
Other comprehensive income:
Net unrealized gains related to available-for-sale securities	1,989	941	3,246	555
Income tax expense	(789)	(364)	(1,273)	(214)
Total	1,200	577	1,973	341
Defined benefit pension items:
Net loss arising during the period	0	(187)	0	(596)
Settlement included in net periodic cost	0	200	0	440
Amortization of loss included in net periodic cost	0	125	0	257
Income tax expense	0	(53)	0	(40)
Total	0	85	0	61
Total other comprehensive income, net of tax	1,200	662	1,973	402
Total comprehensive income (loss), net of tax	$ 929	$ 15,271	$ (13)	$ 417,999