STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Class A	Class B	Common stock Class A	Common stock Class B	Additional paid-in-capital	Accumulated other comprehensive income (loss)	Retained earnings	Retained earnings Class A	Retained earnings Class B	Treasury stock	Deferred compensation
Balance, end of year at Dec. 31, 2012	$ 641,870			$ 1,992	$ 178	$ 16,346	$ (133,191)	$ 1,852,180			$ (1,095,635)	$ 0
Increase (decrease) in shareholders' equity
Net income	162,611							162,611
Other comprehensive income (loss)	74,092						74,092
Dividends declared		$ (112,443)	$ (920)						$ (112,443)	$ (920)
Net purchase of treasury stock	(31,229)					19					(31,248)
Balance, end of year at Dec. 31, 2013	733,981			1,992	178	16,365	(59,099)	1,901,428			(1,126,883)	0
Increase (decrease) in shareholders' equity
Net income	167,505							167,505
Other comprehensive income (loss)	(58,602)						(58,602)
Dividends declared		(119,509)	(986)						(119,509)	(986)
Net purchase of treasury stock	(19,255)					(48)					(19,207)
Balance, end of year at Dec. 31, 2014	703,134			1,992	178	16,317	(117,701)	1,948,438			(1,146,090)	0
Increase (decrease) in shareholders' equity
Net income	174,678							174,678
Other comprehensive income (loss)	20,837						20,837
Dividends declared		$ (128,082)	$ (1,058)						$ (128,082)	$ (1,058)
Net purchase of treasury stock	(6)					(6)					0
Deferred compensation	0										(9,018)	9,018
Balance, end of year at Dec. 31, 2015	$ 769,503			$ 1,992	$ 178	$ 16,311	$ (96,864)	$ 1,993,976			$ (1,155,108)	$ 9,018