Income Taxes - Summary of Income from Continuing Operations before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest [Abstract]
Foreign	$ 54,753	$ 82,919	$ 33,611
United States	10,256	21,431	31,118
Income from continuing operations before income taxes	$ 65,009	$ 104,350	$ 64,729