General - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015 USD ($) reporting_unit
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Revenue major segments percentage	51.00%
Method for estimating unreported policy revenues, period of use (more than)	10 years
Threshold amount for large claims | $	$ 1,000,000.0
Number of reporting units used for goodwill evaluation | reporting_unit	4
Non-cancelable operating lease, expiration period	10 years
Minimum
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Threshold percentage, reserve amount	4.00%
Intangible assets estimated life	3 years
Minimum | Buildings
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life	30 years
Minimum | Furniture and equipment
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life	3 years
Maximum
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Threshold percentage, reserve amount	5.00%
Intangible assets estimated life	10 years
Maximum | Buildings
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life	40 years
Maximum | Furniture and equipment
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Property and equipment, useful life	10 years