Summary of Significant Accounting Policies - Additional Information (Detail)	Jun. 30, 2017 Country State Polilcy
Accounting Policies [Abstract]
Number of countries in which company operates \| Country	20
Number of states in which company licensed to sell insurance and annuities \| State	49
Number of new accounting pronouncements applicable \| Polilcy	0

The number of countries in which the entity operates as of balance sheet date.

No definition available.

Name:	us-gaap_NumberOfCountriesInWhichEntityOperates
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant