Shareholder's Equity (Narrative) (Details) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended						9 Months Ended
	Dec. 31, 2015 USD ($) $ / shares shares	Sep. 30, 2016 USD ($) $ / shares shares	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Sep. 30, 2016 USD ($) installment $ / shares shares	Sep. 30, 2015 USD ($) shares	Jun. 30, 2014 shares
Common Stock:
Repurchase of common stock, shares								83,587	67,000
Repurchase of common stock | $								$ 6,100	$ 3,700
Mandatory Convertible Preferred Stock
Preferred stock dividends | $		$ (2,264)	$ (2,300)	$ (2,300)	$ (2,264)	$ (2,300)	$ (2,300)	$ (6,792)	$ (6,792)
Preferred Stock, Shares Outstanding	1,725,000	1,725,000						1,725,000
Stock Incentive Plans:
Number of shares authorized for grant under share incentive plan		3,200,000						3,200,000		1,200,000
Shares available for future grants/issuance under stock incentive plan		2,408,787						2,408,787
Unrecognized compensation cost on non vested awards | $		$ 36,300						$ 36,300
Weighted average period								1 year 1 month
Number of units granted								586,791
Grant date value of common stock | $ / shares								$ 74.00
Stock Options [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period								4 years
Options term								10 years
Employees [Member] | Restricted Stock [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period								4 years
Number of installments in restricted stock granted. | installment								3
Mandatory Convertible Preferred Stock [Member]
Stock Incentive Plans:
Number of anti-dilutive options		3,100,000						3,100,000	3,100,000
Stock Options [Member]
Stock Incentive Plans:
Number of anti-dilutive options		0			0			0	0
Common Stock [Member]
Issuance of stock (in shares)	5,835,000
Issuance of stock, price per share | $ / shares	$ 80.00
Stock offering expenses | $	$ 19,100
Mandatory Convertible Preferred Stock [Member]
Mandatory Convertible Preferred Stock
Dividend rate								5.25%
Initial liquidation preference (usd per share) | $ / shares		$ 100						$ 100
Consecutive trading day								20 days
Dividends declared (usd per share) | $ / shares		$ 1.3125	$ 1.3125	$ 1.3125	$ 1.3125	$ 1.3125	$ 1.3125
Minimum [Member] | Mandatory Convertible Preferred Stock [Member]
Mandatory Convertible Preferred Stock
Conversion rate		1.8141						1.8141
Maximum [Member] | Mandatory Convertible Preferred Stock [Member]
Mandatory Convertible Preferred Stock
Conversion rate		2.2222						2.2222
Performance-based Restricted Stock Units [Member]
Stock Incentive Plans:
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period								3 years
Number of units granted								74,752
Grant date value of common stock | $ / shares								$ 74.09
Performance goal period for vesting								1 year
Projected vesting percentage								100.00%
Performance-based Restricted Stock Units [Member] | Minimum [Member]
Stock Incentive Plans:
Projected vesting percentage								0.00%
Performance-based Restricted Stock Units [Member] | Maximum [Member]
Stock Incentive Plans:
Projected vesting percentage								150.00%