Debt - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended		0 Months Ended					1 Months Ended
	Jun. 30, 2014 4.98% Senior Notes	Mar. 26, 2014 4.98% Senior Notes	Mar. 26, 2014 Term Loan, 364-day Credit Agreement	Jun. 30, 2014 Line of Credit	Jun. 30, 2014 Line of Credit Amended and Restated Credit Agreement Minimum	Jun. 30, 2014 Line of Credit Amended and Restated Credit Agreement Maximum	Jun. 30, 2014 Line of Credit Credit Agreement Minimum	Jun. 30, 2014 Line of Credit Credit Agreement Maximum	Jun. 30, 2014 Line of Credit Letter of Credit	Jun. 30, 2014 Federal Funds Rate Line of Credit Amended and Restated Credit Agreement	Jun. 30, 2014 Base Rate Line of Credit Amended and Restated Credit Agreement Minimum	Jun. 30, 2014 Base Rate Line of Credit Amended and Restated Credit Agreement Maximum	Jun. 30, 2014 Base Rate Line of Credit Credit Agreement Minimum	Jun. 30, 2014 Base Rate Line of Credit Credit Agreement Maximum	Jun. 30, 2014 Eurodollar Line of Credit Amended and Restated Credit Agreement Minimum	Jun. 30, 2014 Eurodollar Line of Credit Amended and Restated Credit Agreement Maximum	Jun. 30, 2014 Eurodollar Line of Credit Credit Agreement Minimum	Jun. 30, 2014 Eurodollar Line of Credit Credit Agreement Maximum
Debt Instrument
Proceeds from 4.98% Senior Note		$ 175,000,000
Interest Rate	4.98%
Debt Repayment			175,000,000
Debt Instrument, Term			364 days
Debt to Capital Ratio	0.65
Maximum borrowing capacity				$ 525,000,000					$ 125,000,000
Applicable margin										0.50%	0.50%	1.50%	0.80%	1.80%	1.50%	2.50%	1.80%	2.80%
Commitment fee percentage					0.30%	0.45%	0.30%	0.50%