Segment Information - Total Assets by Segment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Assets	$ 6,557,629	$ 6,612,014
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	6,493,176	6,519,239
Operating Segments [Member] | Carolinas [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	338,273	325,690
Operating Segments [Member] | Chicago Milwaukee [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	429,390	422,531
Operating Segments [Member] | Houston [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	522,285	418,154
Operating Segments [Member] | Lehigh Central PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	1,157,468	1,023,641
Operating Segments [Member] | Minnesota [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	346,840	333,506
Operating Segments [Member] | Orlando [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	138,181	160,899
Operating Segments [Member] | Philadelphia [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	444,889	366,243
Operating Segments [Member] | Richmond Hampton Roads [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	128,825	250,205
Operating Segments [Member] | South Florida [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	409,501	400,034
Operating Segments [Member] | Southeastern PA [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	448,523	698,163
Operating Segments [Member] | Tampa [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	326,670	335,652
Operating Segments [Member] | United Kingdom [Member] | UNITED KINGDOM
Segment Reporting Information [Line Items]
Assets	215,850	231,271
Operating Segments [Member] | Other Segments [Member] | North America [Member]
Segment Reporting Information [Line Items]
Assets	1,586,481	1,553,250
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 64,453	$ 92,775