Unaudited Condensed Consolidated Statement of Equity Statement (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Treasury Stock	Capital in Excess of Par Value	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest
Balance at beginning of period at Dec. 31, 2012	$ 1,362,827	$ 211,057	$ (10)	$ 1,307,058	$ (286,795)	$ 111,717	$ 19,800
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	75,888	0	0	0	91,236	(17,260)	1,912
Dividends declared on common stock	(27,553)	0	0	(27,553)	0	0	0
Employee share-based compensation earned	5,850	0	0	5,850	0	0	0
Stock option exercises	4,999	555	0	4,444	0	0	0
Restricted stock awards, net of forfeitures	0	378	(3)	(375)	0	0	0
Purchase of Company common stock	(1,851)	0	(117)	(717)	(1,017)	0	0
Cancellation of Company Stock	0	(8,000)	8,000	0	0	0	0
Tax Benefits Related to Share-Based Awards	5,558	0	0	5,558	0	0	0
Purchase of noncontrolling interest	(8,333)	0	0	1,696	0	0	6,637
Noncontrolling interest payment	(900)	0	0	0	0	0	(900)
Other	1,376	82	0	1,294	0	0	0
Balance at end of period at Jun. 30, 2013	1,417,861	212,064	(122)	1,293,863	(196,576)	94,457	14,175
Balance at beginning of period at Dec. 31, 2013	1,424,378	212,327	(10)	1,259,348	(145,876)	88,441	10,148
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Comprehensive income	75,500	0	0	0	67,024	2,318	6,158
Dividends declared on common stock	(34,024)	0	0	(34,024)	0	0	0
Employee share-based compensation earned	6,423	0	0	6,423	0	0	0
Stock option exercises	15,552	1,605	0	13,947	0	0	0
Restricted stock awards, net of forfeitures	0	345	0	(345)	0	0	0
Purchase of Company common stock	61,186	0	3,185	18,669	39,332	0	0
Cancellation of Company Stock	0	(42,000)	42,000	0	0	0	0
Tax Benefits Related to Share-Based Awards	12,521		0	12,521	0	0	0
Purchase of noncontrolling interest	(15,000)	0	0	7,441	0	0	7,559
Noncontrolling interest payment	(134)	0	0	0	0	0	(134)
Other	1,565	93	0	1,472	0	0	0
Balance at end of period at Jun. 30, 2014	$ 1,425,595	$ 214,328	$ (3,153)	$ 1,233,232	$ (118,184)	$ 90,759	$ 8,613