Condensed Consolidated Statements of Stockholder's Equity - USD ($)		Total		Common stock	Additional paid-in capital	Accumulated other comprehensive income	Retained earnings
Beginning balance at Dec. 31, 2015		$ 1,882,266,000		$ 7,233,000	$ 840,874,000	$ 233,438,000	$ 800,721,000
Increase (Decrease) in Stockholder's Equity
Net income		172,421,000					172,421,000
Other comprehensive income, net of income taxes		406,149,000	[1]			406,149,000
Dividends		(104,831,000)					(104,831,000)
Capital contribution		0
Capital contribution - stock-based compensation		1,059,000			1,059,000
Income tax benefit on stock-based compensation		405,000			405,000
Ending balance at Jun. 30, 2016		2,357,469,000		7,233,000	842,338,000	639,587,000	868,311,000
Beginning balance at Mar. 31, 2016						459,991,000
Increase (Decrease) in Stockholder's Equity
Net income		73,799,000
Other comprehensive income, net of income taxes	[1]	179,596,000
Ending balance at Jun. 30, 2016		2,357,469,000		7,233,000	842,338,000	639,587,000	868,311,000
Beginning balance at Dec. 31, 2016		2,012,321,000		7,293,000	863,031,000	235,875,000	906,122,000
Increase (Decrease) in Stockholder's Equity
Net income		84,652,000					84,652,000
Other comprehensive income, net of income taxes		170,264,000	[1]			170,264,000
Dividends		(137,301,000)					(137,301,000)
Capital contribution		76,429,000			76,429,000
Capital contribution - stock-based compensation		925,000			925,000
Ending balance at Jun. 30, 2017		2,207,290,000		7,293,000	940,385,000	406,139,000	853,473,000
Beginning balance at Mar. 31, 2017						299,854,000
Increase (Decrease) in Stockholder's Equity
Net income		49,824,000
Other comprehensive income, net of income taxes	[1]	106,285,000
Ending balance at Jun. 30, 2017		$ 2,207,290,000		$ 7,293,000	$ 940,385,000	$ 406,139,000	$ 853,473,000

[1] Other comprehensive income includes the non-credit component of impaired gains (losses), net, on fixed maturities available-for-sale in the amounts of $(520) and $(2,472) for the three months ended June 30, 2017, and 2016, respectively and $(1,609) and $(4,367) for the six months ended June 30, 2017, and 2016, respectively.