CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY (Unaudited) - 3 months ended Mar. 31, 2018 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]
Balance at Dec. 31, 2017	$ 66,321	$ 555	$ 25,337	$ (256,363)	$ 296,792
Purchase of treasury stock, at cost	(8,565)	0	0	(8,565)	0
Issuance of long-term incentive awards and dividend equivalents	0	0	(5,764)	6,619	(855)
Stock-based compensation expense	3,135	0	2,840	295	0
Other	351	0	235	116	0
Dividends paid	(8,402)	0	0	0	(8,402)
Unrealized gain on marketable securities, net of tax	1	0	0	0	1
Net income	49,991	0	0	0	49,991
Balance at Mar. 31, 2018	$ 102,832	$ 555	$ 22,648	$ (257,898)	$ 337,527
Balance (shares) at Dec. 31, 2017		55,488
Balance (shares) at Mar. 31, 2018		55,488