Reinsurance (Balance Sheet Reinsurance Results) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Effects of Reinsurance [Line Items]
Reinsurance recoverables	$ 551,288	$ 588,608
Deferred policy acquisition costs	4,345,700	4,344,361
Deferred sales inducements	963,251	978,823
Value of business acquired	29,842	30,287
Other assets	153,999	169,649
Policyholders’ account balances	4,688,654	4,736,889
Future policy benefits	8,144,180	8,686,196
Reinsurance payables	268,455	275,822
Other liabilities	466,354	489,007
Impacts of Reinsurance
Effects of Reinsurance [Line Items]
Reinsurance recoverables	551,288	588,608
Deferred policy acquisition costs	3,569,578	3,557,248
Deferred sales inducements	512,932	520,182
Value of business acquired	(2,344)	(2,357)
Other assets	103,537	112,802
Policyholders’ account balances	2,627,659	2,576,357
Future policy benefits	4,764,632	5,130,753
Reinsurance payables	268,455	275,822
Other liabilities	334,367	335,713
Unaffiliated activity
Effects of Reinsurance [Line Items]
Reinsurance payables	$ 100	$ 100