Long-term Debt Borrowings (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jun. 30, 2014	Mar. 31, 2014
Debt instrument, maturities:
Notes, loans and leases payable	$ 2,185,365	$ 1,942,359
Real estate loan (amortizing term) [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	1.66%
Debt instrument, interest rate, stated percentage rate range, maximum	6.93%
Debt instrument, maturities:
Debt instrument, maturity year	2023
Notes, loans and leases payable	247,500	250,000
Real estate loan (revolving credit) [Member]
Debt instrument, maturities:
Debt instrument, maturity year	2015
Notes, loans and leases payable
Senior mortgages [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	2.15%
Debt instrument, interest rate, stated percentage rate range, maximum	5.75%
Debt instrument, maturities:
Debt instrument, maturity year range, start	2015
Debt instrument, maturity year range, end	2038
Notes, loans and leases payable	809,314	684,915
Working capital loan (revolving credit) [Member]
Debt instrument, maturities:
Debt instrument, maturity year	2016
Notes, loans and leases payable
Fleet loans (amortizing term) [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	1.95%
Debt instrument, interest rate, stated percentage rate range, maximum	5.57%
Debt instrument, maturities:
Debt instrument, maturity year range, start	2015
Debt instrument, maturity year range, end	2021
Notes, loans and leases payable	356,131	370,394
Fleet loans (securitization) [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage (a)	4.90%
Debt instrument, maturities:
Debt instrument, maturity year	2017
Notes, loans and leases payable	87,102	90,793
Fleet loans (revolving credit) [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	1.65%
Debt instrument, interest rate, stated percentage rate range, maximum	1.90%
Debt instrument, maturities:
Debt instrument, maturity year range, start	2017
Debt instrument, maturity year range, end	2018
Notes, loans and leases payable	139,632	89,632
Capital leases (rental equipment) [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	2.23%
Debt instrument, interest rate, stated percentage rate range, maximum	7.83%
Debt instrument, maturities:
Debt instrument, maturity year range, start	2015
Debt instrument, maturity year range, end	2021
Notes, loans and leases payable	504,779	416,750
Other obligations [Member]
Debt instruments, interest rate, stated percentage:
Debt instrument, interest rate, stated percentage rate range, minimum	3.00%
Debt instrument, interest rate, stated percentage rate range, maximum	8.00%
Debt instrument, maturities:
Debt instrument, maturity year range, start	2014
Debt instrument, maturity year range, end	2043
Notes, loans and leases payable	$ 40,907	$ 39,875