Share-Based Compensation (Summarized Information of Stock Options Outstanding) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2012
$10.39 - $28.02
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range - lower range (in dollars per share)	$ 10.39
Exercise price range - upper range (in dollars per share)	$ 28.02
Outstanding:
Weighted average remaining contractual life (years)	6 years 8 months 12 days
Aggregate intrinsic value	$ 27,118
Exercisable:
Number of shares	895
Weighted average remaining contractual life (years)	5 years 1 month 6 days
Aggregate intrinsic value	14,457
Exercised:
Aggregate intrinsic value	9,303
$6.07 - 23.50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range - lower range (in dollars per share)		$ 6.07
Exercise price range - upper range (in dollars per share)		$ 23.50
Outstanding:
Weighted average remaining contractual life (years)			6 years 6 months
Aggregate intrinsic value			30,599
Exercisable:
Number of shares			922
Weighted average remaining contractual life (years)			4 years 6 months
Aggregate intrinsic value			15,053
Exercised:
Aggregate intrinsic value			9,139
$3.68 - 17.50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range - lower range (in dollars per share)				$ 3.68
Exercise price range - upper range (in dollars per share)				$ 17.50
Outstanding:
Weighted average remaining contractual life (years)				6 years 3 months
Aggregate intrinsic value				26,472
Exercisable:
Number of shares				1,040
Weighted average remaining contractual life (years)				4 years 2 months
Aggregate intrinsic value				13,934
Exercised:
Aggregate intrinsic value				$ 10,465