Segment Information - Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Total identifiable assets	$ 1,889,281	$ 1,364,696
North America Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Total identifiable assets	1,214,336	956,807
Europe And Africa Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Total identifiable assets	574,427	363,857
Australia And New Zealand Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Total identifiable assets	79,492
Corporate Segment [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total identifiable assets	$ 21,026	$ 44,032