Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ (23,699)
Stock based-awards	5,462
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(68)
Repurchase of common shares	(696)
Dividends paid	(23,306)
Amortization of deferred pension costs, net of tax	97
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(889)	$ (897)
Net income	15,117	$ 31,042
Ending balance	(27,982)
Common Shares [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,142
Stock based-awards	0
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	0
Repurchase of common shares	0
Dividends paid	0
Amortization of deferred pension costs, net of tax	0
Net income	0
Ending balance	1,142
Additional Paid-In Capital [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0
Stock based-awards	2,424
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(68)
Repurchase of common shares	0
Dividends paid	0
Amortization of deferred pension costs, net of tax	0
Net income	0
Ending balance	2,356
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	219,207
Stock based-awards	0
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	0
Repurchase of common shares	0
Dividends paid	(23,306)
Amortization of deferred pension costs, net of tax	0
Net income	15,082
Ending balance	210,983
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(10,538)
Stock based-awards	0
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	0
Repurchase of common shares	0
Dividends paid	0
Amortization of deferred pension costs, net of tax	97
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(889)
Net income	0
Ending balance	(11,330)
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(238,875)
Stock based-awards	3,038
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	0
Repurchase of common shares	(696)
Dividends paid	0
Amortization of deferred pension costs, net of tax	0
Net income	0
Ending balance	(236,533)
Non-Controlling Interests [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	5,365
Stock based-awards	0
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	0
Repurchase of common shares	0
Dividends paid	0
Amortization of deferred pension costs, net of tax	0
Net income	35
Ending balance	$ 5,400