CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - 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 INCOME	$ 84,735	$ 32,844	$ 208,404	$ 92,439
OTHER COMPREHENSIVE INCOME:
Net reclassification adjustment for amounts recognized in net income as a component of net periodic benefit cost, net of income tax expense of $1,840 and $1,298 for the three months ended June 30, 2015 and 2014, and $3,648 and $2,585 for the six months ended June 30, 2015 and 2014, respectively	3,413	2,424	6,799	4,828
COMPREHENSIVE INCOME	$ 88,148	$ 35,268	$ 215,203	$ 97,267