CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Unrealized loss on available for sale securities, tax	$ 3	$ 4	$ 0
Amortization of prior service cost and actuarial loss for retirement plan included in net periodic pension costs, tax	209	726	0
Net income	41,854	74,052	9,660
OTHER COMPREHENSIVE (LOSS) INCOME, NET OF TAX:
Unrealized loss on available-for-sale securities, net of tax of $3, $4, and none, respectively	(4)	(6)	(31)
Employee benefit plan:
Actuarial (loss) gain on retirement plan	(385)	901	(442)
Amortization of prior service cost and actuarial loss for retirement plan included in net periodic pension costs, net of tax of $209, none and none, respectively	375	439	628
Net change for employee benefit plan	(10)	1,340	186
TOTAL OTHER COMPREHENSIVE (LOSS) INCOME	(14)	1,334	155
COMPREHENSIVE INCOME	$ 41,840	$ 75,386	$ 9,815