Condensed Consolidated Statement Of Changes In Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Shares Held In Treasury [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-Controlling Interests In Subsidiaries [Member]	Era Group [Member]
Balance at Dec. 31, 2012	$ 1,742,675	$ 367	$ 1,330,324	$ 1,473,509	$ (1,088,560)	$ (1,986)	$ 29,021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Employee Stock Purchase Plan	978	0	0	0	978	0	0
Exercise of stock options	7,830	1	7,829	0	0	0	0
Director stock awards	125	0	125	0	0	0	0
Restricted stock and restricted stock units	(25)	2	(27)	0	0	0	0
Stockholders' Equity Note, Spinoff Transaction	(415,371)	0	0	(415,209)	0	(55)	(107)
Stockholders Equity Note Spinoff Transaction, Value, Share Award Settlements for Spin Off	(631)	0	(631)	0	0	0	0
Amortization of share awards	8,810	0	(8,810)	0	0	0	0
Stock Issued During Period, Value, Restricted Stock Award, Forfeitures	0	0	1,479	0	(1,479)	0	0
Issuance of noncontrolling interests	40	0	0	0	0	0	40
Dividends paid to noncontrolling interests	(3,276)	0	0	0	0	0	(3,276)
Comprehensive income:
Net Income (Loss) Attributable to Parent	8,397	0	0		0	0
Net Income (Loss) Attributable to Noncontrolling Interest	(348)						(348)
Net income	8,049							881
Other comprehensive income	(2,654)	0	0	0	0	(2,202)	(452)
Balance at Jun. 30, 2013	$ 1,346,550	$ 370	$ 1,347,909	$ 1,066,697	$ (1,089,061)	$ (4,243)	$ 24,878