Related Party Transactions - Additional Information (Detail) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Jun. 18, 2016	Feb. 25, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Related Party Transaction [Line Items]
Expense incurred as result of multiple service agreements			$ 2,374	$ 2,635	$ 4,788	$ 5,505
Intercompany short-term note receivable settled	$ 25,000	$ 25,000
Interest on intercompany note receivable	0.13%	0.36%
Intercompany short-term note receivable, date	Jun. 19, 2015	Feb. 25, 2016
Interest income accrued and/or received due to intercompany arrangements			10	1	27
AEGON USA Investment Management LLC
Related Party Transaction [Line Items]
Expense incurred as result of multiple service agreements			511	402	1,003	841
AEGON USA Realty Advisors, LLC
Related Party Transaction [Line Items]
Expense incurred as result of multiple service agreements			44	33	86	66
Transamerica Capital, Inc.
Related Party Transaction [Line Items]
Expense incurred as result of multiple service agreements			5,984	7,303	12,136	14,653
Transamerica Asset Management, Inc.
Related Party Transaction [Line Items]
Expense incurred as result of multiple service agreements			5	94	82	186
Distribution and shareholder services agreement
Related Party Transaction [Line Items]
Revenue from participation agreement			$ 509	$ 618	$ 1,000	$ 1,236