Net Contributions (Withdrawals) by Contract Owners (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Contributions Withdrawals By Contract Owners [Line Items]
Contract owner net payments	$ 2,558,086	$ 2,525,497	$ 2,608,256
Policy loans	(1,136,370)	(1,091,254)	(1,388,312)
Policy loan repayments and interest	2,147,513	1,968,387	1,915,714
Surrenders, withdrawals and death benefits	(4,051,642)	(3,289,612)	(2,757,121)
Net transfers from/(to) other subaccounts or fixed rate option	(320,256)	(814,382)	(521,126)
Administrative and other charges	(1,986,090)	(1,963,400)	(2,021,915)
Net Contributions (Withdrawals) by Contract Owners	(2,788,759)	(2,664,764)	(2,164,504)
VAL
Net Contributions Withdrawals By Contract Owners [Line Items]
Contract owner net payments	2,378,436	2,337,323	2,416,579
Policy loans	(1,049,046)	(977,555)	(1,306,853)
Policy loan repayments and interest	1,906,719	1,799,917	1,766,543
Surrenders, withdrawals and death benefits	(3,459,721)	(2,901,725)	(2,457,118)
Net transfers from/(to) other subaccounts or fixed rate option	(301,500)	(818,189)	(506,150)
Administrative and other charges	(1,801,533)	(1,784,351)	(1,849,182)
Net Contributions (Withdrawals) by Contract Owners	(2,326,645)	(2,344,580)	(1,936,181)
VLI
Net Contributions Withdrawals By Contract Owners [Line Items]
Contract owner net payments	179,650	188,174	195,178
Policy loans	(54,592)	(61,239)	(53,677)
Policy loan repayments and interest	85,486	130,567	76,993
Surrenders, withdrawals and death benefits	(246,562)	(257,524)	(122,013)
Net transfers from/(to) other subaccounts or fixed rate option	(19,143)	(34,163)	(10,834)
Administrative and other charges	(170,547)	(164,272)	(158,241)
Net Contributions (Withdrawals) by Contract Owners	(225,708)	(198,457)	(72,594)
SPVA
Net Contributions Withdrawals By Contract Owners [Line Items]
Contract owner net payments	0	0	0
Policy loans	0	0	0
Policy loan repayments and interest	0	0	0
Surrenders, withdrawals and death benefits	(3,818)	(6,537)	(3,443)
Net transfers from/(to) other subaccounts or fixed rate option	0	0	0
Administrative and other charges	0	0	0
Net Contributions (Withdrawals) by Contract Owners	(3,818)	(6,537)	(3,443)
SPVL
Net Contributions Withdrawals By Contract Owners [Line Items]
Contract owner net payments	0	0	(3,501)
Policy loans	(32,732)	(52,460)	(27,782)
Policy loan repayments and interest	155,308	37,903	72,178
Surrenders, withdrawals and death benefits	(341,541)	(123,826)	(174,547)
Net transfers from/(to) other subaccounts or fixed rate option	387	37,970	(4,142)
Administrative and other charges	(14,010)	(14,777)	(14,492)
Net Contributions (Withdrawals) by Contract Owners	$ (232,588)	$ (115,190)	$ (152,286)