Benefit Plans Benefit Plans (Detail 1) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	$ 1,063,722	$ 979,417	$ 975,956
Defined Benefit Plans, Service Cost and Other	30,165	30,368
Defined Benefit Plan, Interest Cost	12,955	15,168	20,641
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	40,033	43,949
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	(15,016)	150
Defined Benefit Plan, Benefit Obligation, Benefits Paid	38,395	56,773
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	54,563	(29,401)
Defined Benefit Plan, Fair Value of Plan Assets	919,782	820,272	844,715
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	63,924	22,803
Defined Benefit Plan, Plan Assets, Contributions by Employer	23,458	23,046
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	13,640	13,427
Defined Benefit Plan, Plan Assets, Benefits Paid	38,395	56,773
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	36,883	(26,946)
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(143,940)	(159,145)
Pension Plan [Member] \| Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	918,478	838,277	818,269
Defined Benefit Plans, Service Cost and Other	29,600	29,936
Defined Benefit Plan, Interest Cost	8,511	10,664	14,071
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	33,036	42,786
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	(15,153)	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid	30,356	33,977
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	54,563	(29,401)
Defined Benefit Plan, Fair Value of Plan Assets	808,215	716,169	725,597
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	49,055	15,927
Defined Benefit Plan, Plan Assets, Contributions by Employer	22,961	22,291
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	13,503	13,277
Defined Benefit Plan, Plan Assets, Benefits Paid	30,356	33,977
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	36,883	(26,946)
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(110,263)	(122,108)
Pension Plan [Member] \| Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	142,571	138,155	154,415
Defined Benefit Plans, Service Cost and Other	565	432
Defined Benefit Plan, Interest Cost	4,374	4,428	6,431
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	6,979	845
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	0	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid	7,502	21,965
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	0	0
Defined Benefit Plan, Fair Value of Plan Assets	111,567	104,103	119,118
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	14,869	6,876
Defined Benefit Plan, Plan Assets, Contributions by Employer	97	74
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Benefits Paid	7,502	21,965
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	0	0
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(31,004)	(34,052)
Other Postretirement Benefits Plan [Member] \| Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation	2,673	2,985	3,272
Defined Benefit Plans, Service Cost and Other	0	0
Defined Benefit Plan, Interest Cost	70	76	139
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)	18	318
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment	137	150
Defined Benefit Plan, Benefit Obligation, Benefits Paid	537	831
Defined Benefit Plan, Benefit Obligation, Foreign Currency Translation Gain (Loss)	0	0
Defined Benefit Plan, Fair Value of Plan Assets	0	0	$ 0
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)	0	0
Defined Benefit Plan, Plan Assets, Contributions by Employer	400	681
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	137	150
Defined Benefit Plan, Plan Assets, Benefits Paid	537	831
Defined Benefit Plan, Plan Assets, Foreign Currency Translation Gain (Loss)	0	0
Defined Benefit Plan, Funded (Unfunded) Status of Plan	$ (2,673)	$ (2,985)

The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period and other deminimus expenses. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

No definition available.