Accumulated Other Comprehensive Income/(Loss) AOCI Attributbale to G&W (Details) - USD ($) $ in Thousands	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016
Accumulated other comprehensive loss, beginning balance	$ (211,336)	$ (153,457)
Other comprehensive loss before reclassifications	46,771	(6,131)
Amounts reclassified from accumulated other comprehensive loss, net of tax(provision)/benefit	5,105	(8,673)
OCI, Net of Tax, Portion Attributable to Parent	51,876	(14,804)
Accumulated other comprehensive income loss, ending balance	(159,460)	(168,261)
Foreign Currency Translation Adjustment [Member]
Accumulated other comprehensive loss, beginning balance	(177,662)	(156,146)
Other comprehensive loss before reclassifications	53,482	(1,491)
Amounts reclassified from accumulated other comprehensive loss, net of tax(provision)/benefit	0	0
OCI, Net of Tax, Portion Attributable to Parent	53,482	(1,491)
Accumulated other comprehensive income loss, ending balance	(124,180)	(157,637)
Defined Benefit Plans [Member]
Accumulated other comprehensive loss, beginning balance	(19,948)	11,005
Other comprehensive loss before reclassifications	(2,263)	0
Amounts reclassified from accumulated other comprehensive loss, net of tax(provision)/benefit	76	2,924
OCI, Net of Tax, Portion Attributable to Parent	(2,187)	2,924
Accumulated other comprehensive income loss, ending balance	(22,135)	13,929
Tax provision on amounts reclassified from AOCI for defined benefit plans	(40)	(791)
Net Unrealized Gain/(Loss) on Cash Flow Hedges [Member]
Accumulated other comprehensive loss, beginning balance	(13,726)	(8,316)
Other comprehensive loss before reclassifications	(4,448)	(4,640)
Amounts reclassified from accumulated other comprehensive loss, net of tax(provision)/benefit	5,029	(11,597)
OCI, Net of Tax, Portion Attributable to Parent	581	(16,237)
Accumulated other comprehensive income loss, ending balance	(13,145)	(24,553)
Tax (provision)/benefit on amounts reclassified from AOCI for cash flow hedges	$ (3,381)	$ 7,731

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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