Income Taxes - Recognized in Comprehensive Income (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Unrealized gain/(loss) on cash flow hedges		$ 4,808	$ (1,543)
Retirement benefits		(9)	(109)
Total Income tax benefit/(expense) recognized in other comprehensive income	[1]	$ 4,799	$ (1,652)

[1] These are income tax benefit/(expense) recognized on cash flow hedges and retirement benefits. Refer to Note 21 to the unaudited consolidated financial statements.