Income Taxes - NOL, foreign earnings (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Income Taxes [Line Items]
Unremitted earnings of foreign subsidiaries	$ 47.6
Unrecognized deferred tax liability for foreign earnings	8.4
U.S.
Income Taxes [Line Items]
Net operating loss carryforward	7.2
U.K.
Income Taxes [Line Items]
Net operating loss carryforward	14.7
Mexico
Income Taxes [Line Items]
Net operating loss carryforward	$ 9.3
Carryforward period	10 years