Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 85,571	$ 69,436	$ 32,200
Other comprehensive income (loss):
Reclassification adjustment for losses included in net income (Pension termination)	0	2,519	0
Net loss arising during the period	0	0	(2,570)
Reclassification adjustment for losses included in net income (Interest expense)	168	115	0
Losses on settlement of swaps arising during the period	0	(1,684)	0
Other comprehensive income (loss)	168	950	(2,570)
COMPREHENSIVE INCOME	85,739	70,386	29,630
Less: Comprehensive income attributable to noncontrolling interests			(313)
COMPREHENSIVE INCOME ATTRIBUTABLE TO COMMON STOCKHOLDERS	$ 85,739	$ 70,386	$ 29,317