Incentive and Deferred Compensation Plans (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Awards, employer match, and hypothetical earnings by plan:
Total plan awards and earnings	$ 18,663	$ 23,327	$ 21,534
Total plan awards paid	(20,418)	(14,317)	(14,839)
Gross incentive plan and deferred compensation liabilities at end of period	32,908	37,457	38,978
Annual incentive plan
Awards, employer match, and hypothetical earnings by plan:
Annual incentive plan awards	6,460	7,057	6,222
Long-term incentive plan
Awards, employer match, and hypothetical earnings by plan:
Long-term incentive plan awards	11,321	14,228	12,523
Forfeitures	(3,117)	(821)
Deferred compensation plans and stock compensation plan for outside directors
Awards, employer match, and hypothetical earnings by plan:
Deferred compensation plans, employer match, and hypothetical earnings	882	2,042	2,789
Compensation deferred under the plans	1,496	996	527
Distributions from the deferred compensation plans	(435)	(1,688)	$ (1,072)
Funding of rabbi trust for outside directors	$ (738)	$ (9,018)