Amount of interest capitalized during the period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Allowance for Funds Used during Construction
-URI http://asc.fasb.org/extlink&oid=6504829

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Name:	us-gaap_InterestCostsCapitalized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Summary of Significant Accounting Policies - Investment Properties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investment properties
Capitalized interest	$ 32,664	$ 16,500	$ 15,585
Buildings and improvements \| Minimum
Investment properties
Useful life	10 years
Buildings and improvements \| Maximum
Investment properties
Useful life	35 years
Equipment and fixtures \| Minimum
Investment properties
Useful life	7 years
Equipment and fixtures \| Maximum
Investment properties
Useful life	10 years