Shareholders' Equity (Details) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011
Reconciliation of the beginning and end of the period equity accounts
Balance at December 31, 2010	$ 523,050
Net income	28,538
Other comprehensive income	31,521
Acquisition of business	37,853
Acquisition of noncontrolling shareholder interest	(116,500)
Stock compensation plans, including tax benefit of $322	2,514
Cash dividends - $.210 per share	(13,048)
Balance at June 30, 2011	493,928
Parent [Member]
Reconciliation of the beginning and end of the period equity accounts
Balance at December 31, 2010	460,789
Net income	27,197
Other comprehensive income	30,255
Acquisition of noncontrolling shareholder interest	(54,239)
Stock compensation plans, including tax benefit of $322	2,514
Cash dividends - $.210 per share	(13,048)
Balance at June 30, 2011	453,468
Noncontrolling Interest [Member]
Reconciliation of the beginning and end of the period equity accounts
Balance at December 31, 2010	62,261
Net income	1,341
Other comprehensive income	1,266
Acquisition of business	37,853
Acquisition of noncontrolling shareholder interest	(62,261)
Balance at June 30, 2011	40,460
Redeemable Noncontrolling Shareholders' Interests [Member]
Reconciliation of the beginning and end of the period equity accounts
Balance at December 31, 2010	71,442
Net income	4,386
Other comprehensive income	1,576
Dividends payable to noncontrolling shareholders	(5,731)
Balance at June 30, 2011	$ 71,673