Segment Information - Consolidated Total Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	$ 3,773,788	$ 3,376,293
Cash and cash equivalents	103,367	104,522	$ 185,488	$ 161,020
Reportable Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	3,670,421	3,271,771
Reportable Segment | Global Solutions
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	2,618,759	2,870,998
Reportable Segment | Global Products
Segment Reporting, Asset Reconciling Item [Line Items]
Assets	1,051,662	400,773
Segment Reconciling Items
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	$ 103,367	$ 104,522