Consolidated Statements of Stockholders' Equity (unaudited) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Consolidated Statements of Stockholders' Equity (unaudited) [Abstract]
Cash dividends - per share (in dollars per share)	$ 0.2	$ 0.2
Net issuance of shares for acquisition (in shares)	10,346,363
Treasury stock reissued in acquisition of Alliance (in shares)	408,957
Net issuance of shares to employee benefit plans and other stock plans, including tax benefit (in shares)	28,339	83,850