Condensed Consolidated Statements of Stockholders’ Equity (USD $) In Thousands	Total	Preferred Stock	Unrestricted Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Beginning of Period at Dec. 31, 2013	$ 284,517	$ 0	$ 919	$ 90,985	$ 349,290	$ (155,627)	$ (1,050)
Cash dividends on common stock	(31,307)				(31,307)
Share-based Compensation	11,370			11,370
Excess Tax Benefit from Share-based Compensation, Financing Activities	3,531			3,531
Issuance of vested restricted stock granted to employees	0		7	(7)
Purchase of unrestricted common stock from employees to fulfill employee tax obligations	(8,291)					(8,291)
Purchase Of Unrestricted Common Stock	(88,272)					(88,272)
Net income	92,005				92,005
Post-retirement benefit obligation adjustment—net of tax	338						338
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest End of Period at Jun. 30, 2014	$ 263,891	$ 0	$ 926	$ 105,879	$ 409,988	$ (252,190)	$ (712)