Real Estate and Lending Activities - Disposals - Additional Information (Detail) $ in Millions	Mar. 31, 2017 USD ($)
Business Combinations [Abstract]
Proceeds from sale of facilities	$ 64.0
Gain on real estate dispositions	7.4
Gain offset by non-cash charges	$ 0.6

Cash received for the sale of real estate that is not part of an investing activity during the current period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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