Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income		$ 16,788	$ 13,820
Other comprehensive income:
Unrealized gain on effective cash flow hedges, net of taxes $1,951 and $403, respectively		6,772	2,034
Foreign currency translation adjustment		11,643	1,033
Retirement benefits, net of taxes nil and $5, respectively		0	182
Reclassification adjustments
Realized (gain) on cash flow hedges, net of taxes ($191) and ($25), respectively(1)	[1]	(433)	(32)
Retirement benefits, net of taxes $7 and $1, respectively(2)	[2]	62	21
Total other comprehensive income		18,044	3,238
Total comprehensive income		$ 34,832	$ 17,058

[1] These are reclassified to net income and are included in the foreign exchange gain in the unaudited consolidated statements of income. See Note 13 to the unaudited consolidated financial statements.

[2] These are reclassified to net income and are included in the computation of net periodic pension costs in the unaudited consolidated statements of income. See Note 16 to the unaudited consolidated financial statements