Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income		$ 61,733	$ 51,565	$ 32,445
Other comprehensive income/(loss):
Unrealized gain/(loss) on effective cash flow hedges, net of taxes $1,184, ($402) and $1,768, respectively		2,711	(709)	5,002
Foreign currency translation adjustment		(9,236)	(12,510)	(5,462)
Retirement benefits, net of taxes ($204), $22 and ($28), respectively		(439)	584	(34)
Reclassification adjustments
Realized (gain)/loss on cash flow hedges, net of taxes ($639), $456 and $1,571, respectively(1)	[1]	(795)	661	5,569
Retirement benefits, net of taxes $63, $53 and $15, respectively(2)	[2]	27	158	134
Total other comprehensive (loss)/income		(7,732)	(11,816)	5,209
Total comprehensive income		$ 54,001	$ 39,749	$ 37,654

[1] These are reclassified to net income and are included in the foreign exchange gain/(loss) in the consolidated statements of income. See Note 12 to the consolidated financial statements.

[2] These are reclassified to net income and are included in the computation of net periodic pension costs in the consolidated statements of income. See Note 15 to the consolidated financial statements.