CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) (USD $) In Thousands, unless otherwise specified	Total	Common Stock Issued	Common Stock Treasury	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Balances at Dec. 31, 2013	$ 597,555	$ 140,248	$ (746,237)	$ 159,025	$ 1,372,041	$ (370,615)	$ 43,093
Increase (Decrease) in Stockholders' Equity
Net income	11,613				10,211		1,402
Cash dividends declared:
Common @ $0.205 per share	(16,572)				(16,572)
Noncontrolling interests	(133)						(133)
Other comprehensive income, net of deferred income taxes of $(6,259) and $(118) in 2015 and 2014, respectively	(1,557)					(1,257)	(300)
Contributions from noncontrolling interests	1,560						1,560
Noncontrolling interests transferred in the Infrastructure Transaction	(905)						(905)
Vesting of restricted stock units and other, net 23,962 shares and 39,941 shares in 2015 and 2014, respectively	1,057	79	(593)	1,571
Amortization of unearned portion of stock-based compensation, net of forfeitures	452			452
Balances at Mar. 31, 2014	593,070	140,327	(746,830)	161,048	1,365,680	(371,872)	44,717
Balances at Dec. 31, 2014	351,910	140,444	(749,815)	165,666	1,283,549	(532,256)	44,322
Increase (Decrease) in Stockholders' Equity
Net income	15,829				15,264		565
Cash dividends declared:
Common @ $0.205 per share	(16,348)				(16,348)
Other comprehensive income, net of deferred income taxes of $(6,259) and $(118) in 2015 and 2014, respectively	4,017					4,781	(764)
Contributions from noncontrolling interests	2,100						2,100
Vesting of restricted stock units and other, net 23,962 shares and 39,941 shares in 2015 and 2014, respectively	(228)	45	(192)	(81)
Treasury shares repurchased, 596,632 shares	(10,220)		(10,220)
Amortization of unearned portion of stock-based compensation, net of forfeitures	761			761
Balances at Mar. 31, 2015	$ 347,821	$ 140,489	$ (760,227)	$ 166,346	$ 1,282,465	$ (527,475)	$ 46,223