Employee Benefit Plans - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Age	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	$ 460,733	$ 416,280
One-time non-cash charge	8,000
Pension plans, accumulated other comprehensive income (loss)	13,000
Pension related adjustments	0	(5,454)	$ (7,650)
Expense related to defined contribution savings plans	40,000	39,000	38,000
Deferred compensation	59,803	62,680
Non-qualified supplemental pension plan
Defined Benefit Plan Disclosure [Line Items]
Accrued pension liability	53,000	55,000
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Pension settlement expense	0	71,299
Reduction to projected benefit obligation	0	66,423
Net actuarial loss to be recognized	(32,000)
Required pension contributions to our pension plans	32,000
Benefit obligation	$ 2,135,143	2,298,902	2,228,762
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Maximum age limit of qualified retirees for health care benefits | Age	65
Benefit obligation	$ 19,000	21,000
Company Administered Plan [Member] | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Pension settlement expense	$ 3,061	0	$ 0
United States
Defined Benefit Plan Disclosure [Line Items]
U.S. pension plan assets percentage of total pension plan assets	72.00%
Rabbi Trusts [Member] | Deferred Compensation Arrangement with Individual, by Type of Compensation, Pension and Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Assets held in trust	$ 60,000	63,000
Value of common stock issued in trust	$ 1,000	$ 2,000