Business Segment Information - Property And Equipment Net Of Accumulated Depreciation By Geographic Region (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property and equipment, net	$ 1,651,610	$ 1,603,009
United States [Member]
Segment Reporting Information [Line Items]
Property and equipment, net	956,458	1,024,691
United Kingdom [Member]
Segment Reporting Information [Line Items]
Property and equipment, net	299,699	352,740
Singapore [Member]
Segment Reporting Information [Line Items]
Property and equipment, net	194,649	112,313
Other [Member]
Segment Reporting Information [Line Items]
Property and equipment, net	$ 200,804	$ 113,265